diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
index dc2eb17589c66..f62b8d1d57620 100644
--- a/compiler/rustc_ast_passes/src/ast_validation.rs
+++ b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -1741,7 +1741,7 @@ fn deny_equality_constraints(
                         .map(|segment| segment.ident.name)
                         .zip(poly.trait_ref.path.segments.iter().map(|segment| segment.ident.name))
                         .all(|(a, b)| a == b)
-                        && let Some(potential_assoc) = full_path.segments.iter().last()
+                        && let Some(potential_assoc) = full_path.segments.last()
                     {
                         suggest(poly, potential_assoc, predicate);
                     }
diff --git a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
index af71db6948329..0b3151fd8b82d 100644
--- a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
@@ -518,7 +518,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                     .with_span_help(
                         self.get_closure_bound_clause_span(*def_id),
                         "`Fn` and `FnMut` closures require captured values to be able to be \
-                         consumed multiple times, but an `FnOnce` consume them only once",
+                         consumed multiple times, but `FnOnce` closures may consume them only once",
                     )
             }
             _ => {
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 98be37fd84b59..e579370ce4ef6 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -1113,7 +1113,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
             .map(|snippet| {
                 debug_assert!(
                     !(sp.is_empty() && snippet.is_empty()),
-                    "Span must not be empty and have no suggestion"
+                    "Span `{sp:?}` must not be empty and have no suggestion"
                 );
                 Substitution { parts: vec![SubstitutionPart { snippet, span: sp }] }
             })
diff --git a/compiler/rustc_macros/src/diagnostics/utils.rs b/compiler/rustc_macros/src/diagnostics/utils.rs
index 060799e981d46..c310b99d53513 100644
--- a/compiler/rustc_macros/src/diagnostics/utils.rs
+++ b/compiler/rustc_macros/src/diagnostics/utils.rs
@@ -146,7 +146,7 @@ impl<'ty> FieldInnerTy<'ty> {
             };
 
             let path = &ty_path.path;
-            let ty = path.segments.iter().last().unwrap();
+            let ty = path.segments.last().unwrap();
             let syn::PathArguments::AngleBracketed(bracketed) = &ty.arguments else {
                 panic!("expected bracketed generic arguments");
             };
diff --git a/compiler/rustc_parse/messages.ftl b/compiler/rustc_parse/messages.ftl
index 3a21eea3d0aee..9e0075c21b9ed 100644
--- a/compiler/rustc_parse/messages.ftl
+++ b/compiler/rustc_parse/messages.ftl
@@ -862,8 +862,8 @@ parse_too_many_hashes = too many `#` symbols: raw strings may be delimited by up
 
 parse_too_short_hex_escape = numeric character escape is too short
 
-parse_trailing_vert_not_allowed = a trailing `|` is not allowed in an or-pattern
-    .suggestion = remove the `{$token}`
+parse_trailing_vert_not_allowed = a trailing `{$token}` is not allowed in an or-pattern
+parse_trailing_vert_not_allowed_suggestion = remove the `{$token}`
 
 parse_trait_alias_cannot_be_auto = trait aliases cannot be `auto`
 parse_trait_alias_cannot_be_const = trait aliases cannot be `const`
diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index a07d0606fd0f4..a105dd1909e93 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -2661,7 +2661,7 @@ pub(crate) enum TopLevelOrPatternNotAllowedSugg {
         parse_sugg_remove_leading_vert_in_pattern,
         code = "",
         applicability = "machine-applicable",
-        style = "verbose"
+        style = "tool-only"
     )]
     RemoveLeadingVert {
         #[primary_span]
@@ -2694,12 +2694,25 @@ pub(crate) struct UnexpectedVertVertInPattern {
     pub start: Option<Span>,
 }
 
+#[derive(Subdiagnostic)]
+#[suggestion(
+    parse_trailing_vert_not_allowed,
+    code = "",
+    applicability = "machine-applicable",
+    style = "tool-only"
+)]
+pub(crate) struct TrailingVertSuggestion {
+    #[primary_span]
+    pub span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(parse_trailing_vert_not_allowed)]
 pub(crate) struct TrailingVertNotAllowed {
     #[primary_span]
-    #[suggestion(code = "", applicability = "machine-applicable", style = "verbose")]
     pub span: Span,
+    #[subdiagnostic]
+    pub suggestion: TrailingVertSuggestion,
     #[label(parse_label_while_parsing_or_pattern_here)]
     pub start: Option<Span>,
     pub token: Token,
diff --git a/compiler/rustc_parse/src/parser/cfg_select.rs b/compiler/rustc_parse/src/parser/cfg_select.rs
index 2c6fb224d70d6..08a71db4de853 100644
--- a/compiler/rustc_parse/src/parser/cfg_select.rs
+++ b/compiler/rustc_parse/src/parser/cfg_select.rs
@@ -1,11 +1,12 @@
 use rustc_ast::token::Token;
 use rustc_ast::tokenstream::{TokenStream, TokenTree};
+use rustc_ast::util::classify;
 use rustc_ast::{MetaItemInner, token};
 use rustc_errors::PResult;
 use rustc_span::Span;
 
 use crate::exp;
-use crate::parser::Parser;
+use crate::parser::{AttrWrapper, ForceCollect, Parser, Restrictions, Trailing, UsePreAttrPos};
 
 pub enum CfgSelectPredicate {
     Cfg(MetaItemInner),
@@ -23,19 +24,26 @@ pub struct CfgSelectBranches {
     pub unreachable: Vec<(CfgSelectPredicate, TokenStream, Span)>,
 }
 
-/// Parses a `TokenTree` that must be of the form `{ /* ... */ }`, and returns a `TokenStream` where
-/// the surrounding braces are stripped.
+/// Parses a `TokenTree` consisting either of `{ /* ... */ }` (and strip the braces) or an
+/// expression followed by a comma (and strip the comma).
 fn parse_token_tree<'a>(p: &mut Parser<'a>) -> PResult<'a, TokenStream> {
-    // Generate an error if the `=>` is not followed by `{`.
-    if p.token != token::OpenBrace {
-        p.expect(exp!(OpenBrace))?;
+    if p.token == token::OpenBrace {
+        // Strip the outer '{' and '}'.
+        match p.parse_token_tree() {
+            TokenTree::Token(..) => unreachable!("because of the expect above"),
+            TokenTree::Delimited(.., tts) => return Ok(tts),
+        }
     }
-
-    // Strip the outer '{' and '}'.
-    match p.parse_token_tree() {
-        TokenTree::Token(..) => unreachable!("because of the expect above"),
-        TokenTree::Delimited(.., tts) => Ok(tts),
+    let expr = p.collect_tokens(None, AttrWrapper::empty(), ForceCollect::Yes, |p, _| {
+        p.parse_expr_res(Restrictions::STMT_EXPR, AttrWrapper::empty())
+            .map(|(expr, _)| (expr, Trailing::No, UsePreAttrPos::No))
+    })?;
+    if !classify::expr_is_complete(&expr) && p.token != token::CloseBrace && p.token != token::Eof {
+        p.expect(exp!(Comma))?;
+    } else {
+        let _ = p.eat(exp!(Comma));
     }
+    Ok(TokenStream::from_ast(&expr))
 }
 
 pub fn parse_cfg_select<'a>(p: &mut Parser<'a>) -> PResult<'a, CfgSelectBranches> {
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index a415849b91517..9754691a0b9ca 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -24,10 +24,10 @@ use crate::errors::{
     GenericArgsInPatRequireTurbofishSyntax, InclusiveRangeExtraEquals, InclusiveRangeMatchArrow,
     InclusiveRangeNoEnd, InvalidMutInPattern, ParenRangeSuggestion, PatternOnWrongSideOfAt,
     RemoveLet, RepeatedMutInPattern, SwitchRefBoxOrder, TopLevelOrPatternNotAllowed,
-    TopLevelOrPatternNotAllowedSugg, TrailingVertNotAllowed, UnexpectedExpressionInPattern,
-    UnexpectedExpressionInPatternSugg, UnexpectedLifetimeInPattern, UnexpectedParenInRangePat,
-    UnexpectedParenInRangePatSugg, UnexpectedVertVertBeforeFunctionParam,
-    UnexpectedVertVertInPattern, WrapInParens,
+    TopLevelOrPatternNotAllowedSugg, TrailingVertNotAllowed, TrailingVertSuggestion,
+    UnexpectedExpressionInPattern, UnexpectedExpressionInPatternSugg, UnexpectedLifetimeInPattern,
+    UnexpectedParenInRangePat, UnexpectedParenInRangePatSugg,
+    UnexpectedVertVertBeforeFunctionParam, UnexpectedVertVertInPattern, WrapInParens,
 };
 use crate::parser::expr::{DestructuredFloat, could_be_unclosed_char_literal};
 use crate::{exp, maybe_recover_from_interpolated_ty_qpath};
@@ -267,10 +267,9 @@ impl<'a> Parser<'a> {
 
         if let PatKind::Or(pats) = &pat.kind {
             let span = pat.span;
-            let sub = if pats.len() == 1 {
-                Some(TopLevelOrPatternNotAllowedSugg::RemoveLeadingVert {
-                    span: span.with_hi(span.lo() + BytePos(1)),
-                })
+            let sub = if let [_] = &pats[..] {
+                let span = span.with_hi(span.lo() + BytePos(1));
+                Some(TopLevelOrPatternNotAllowedSugg::RemoveLeadingVert { span })
             } else {
                 Some(TopLevelOrPatternNotAllowedSugg::WrapInParens {
                     span,
@@ -362,6 +361,9 @@ impl<'a> Parser<'a> {
                 self.dcx().emit_err(TrailingVertNotAllowed {
                     span: self.token.span,
                     start: lo,
+                    suggestion: TrailingVertSuggestion {
+                        span: self.prev_token.span.shrink_to_hi().with_hi(self.token.span.hi()),
+                    },
                     token: self.token,
                     note_double_vert: self.token.kind == token::OrOr,
                 });
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index cc30939f5e96c..ca9c124fca63c 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -16,6 +16,7 @@
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
+#![feature(default_field_values)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(rustc_attrs)]
@@ -1075,7 +1076,7 @@ pub struct Resolver<'ra, 'tcx> {
     /// Assert that we are in speculative resolution mode.
     assert_speculative: bool,
 
-    prelude: Option<Module<'ra>>,
+    prelude: Option<Module<'ra>> = None,
     extern_prelude: FxIndexMap<Macros20NormalizedIdent, ExternPreludeEntry<'ra>>,
 
     /// N.B., this is used only for better diagnostics, not name resolution itself.
@@ -1087,10 +1088,10 @@ pub struct Resolver<'ra, 'tcx> {
     field_visibility_spans: FxHashMap<DefId, Vec<Span>>,
 
     /// All imports known to succeed or fail.
-    determined_imports: Vec<Import<'ra>>,
+    determined_imports: Vec<Import<'ra>> = Vec::new(),
 
     /// All non-determined imports.
-    indeterminate_imports: Vec<Import<'ra>>,
+    indeterminate_imports: Vec<Import<'ra>> = Vec::new(),
 
     // Spans for local variables found during pattern resolution.
     // Used for suggestions during error reporting.
@@ -1141,19 +1142,19 @@ pub struct Resolver<'ra, 'tcx> {
 
     /// Maps glob imports to the names of items actually imported.
     glob_map: FxIndexMap<LocalDefId, FxIndexSet<Symbol>>,
-    glob_error: Option<ErrorGuaranteed>,
-    visibilities_for_hashing: Vec<(LocalDefId, Visibility)>,
+    glob_error: Option<ErrorGuaranteed> = None,
+    visibilities_for_hashing: Vec<(LocalDefId, Visibility)> = Vec::new(),
     used_imports: FxHashSet<NodeId>,
     maybe_unused_trait_imports: FxIndexSet<LocalDefId>,
 
     /// Privacy errors are delayed until the end in order to deduplicate them.
-    privacy_errors: Vec<PrivacyError<'ra>>,
+    privacy_errors: Vec<PrivacyError<'ra>> = Vec::new(),
     /// Ambiguity errors are delayed for deduplication.
-    ambiguity_errors: Vec<AmbiguityError<'ra>>,
+    ambiguity_errors: Vec<AmbiguityError<'ra>> = Vec::new(),
     /// `use` injections are delayed for better placement and deduplication.
-    use_injections: Vec<UseError<'tcx>>,
+    use_injections: Vec<UseError<'tcx>> = Vec::new(),
     /// Crate-local macro expanded `macro_export` referred to by a module-relative path.
-    macro_expanded_macro_export_errors: BTreeSet<(Span, Span)>,
+    macro_expanded_macro_export_errors: BTreeSet<(Span, Span)> = BTreeSet::new(),
 
     arenas: &'ra ResolverArenas<'ra>,
     dummy_binding: NameBinding<'ra>,
@@ -1205,9 +1206,9 @@ pub struct Resolver<'ra, 'tcx> {
     /// Avoid duplicated errors for "name already defined".
     name_already_seen: FxHashMap<Symbol, Span>,
 
-    potentially_unused_imports: Vec<Import<'ra>>,
+    potentially_unused_imports: Vec<Import<'ra>> = Vec::new(),
 
-    potentially_unnecessary_qualifications: Vec<UnnecessaryQualification<'ra>>,
+    potentially_unnecessary_qualifications: Vec<UnnecessaryQualification<'ra>> = Vec::new(),
 
     /// Table for mapping struct IDs into struct constructor IDs,
     /// it's not used during normal resolution, only for better error reporting.
@@ -1216,7 +1217,7 @@ pub struct Resolver<'ra, 'tcx> {
 
     lint_buffer: LintBuffer,
 
-    next_node_id: NodeId,
+    next_node_id: NodeId = CRATE_NODE_ID,
 
     node_id_to_def_id: NodeMap<Feed<'tcx, LocalDefId>>,
 
@@ -1234,17 +1235,17 @@ pub struct Resolver<'ra, 'tcx> {
     item_generics_num_lifetimes: FxHashMap<LocalDefId, usize>,
     delegation_fn_sigs: LocalDefIdMap<DelegationFnSig>,
 
-    main_def: Option<MainDefinition>,
+    main_def: Option<MainDefinition> = None,
     trait_impls: FxIndexMap<DefId, Vec<LocalDefId>>,
     /// A list of proc macro LocalDefIds, written out in the order in which
     /// they are declared in the static array generated by proc_macro_harness.
-    proc_macros: Vec<LocalDefId>,
+    proc_macros: Vec<LocalDefId> = Vec::new(),
     confused_type_with_std_module: FxIndexMap<Span, Span>,
     /// Whether lifetime elision was successful.
     lifetime_elision_allowed: FxHashSet<NodeId>,
 
     /// Names of items that were stripped out via cfg with their corresponding cfg meta item.
-    stripped_cfg_items: Vec<StrippedCfgItem<NodeId>>,
+    stripped_cfg_items: Vec<StrippedCfgItem<NodeId>> = Vec::new(),
 
     effective_visibilities: EffectiveVisibilities,
     doc_link_resolutions: FxIndexMap<LocalDefId, DocLinkResMap>,
@@ -1558,9 +1559,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             field_defaults: Default::default(),
             field_visibility_spans: FxHashMap::default(),
 
-            determined_imports: Vec::new(),
-            indeterminate_imports: Vec::new(),
-
             pat_span_map: Default::default(),
             partial_res_map: Default::default(),
             import_res_map: Default::default(),
@@ -1579,16 +1577,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             ast_transform_scopes: FxHashMap::default(),
 
             glob_map: Default::default(),
-            glob_error: None,
-            visibilities_for_hashing: Default::default(),
             used_imports: FxHashSet::default(),
             maybe_unused_trait_imports: Default::default(),
 
-            privacy_errors: Vec::new(),
-            ambiguity_errors: Vec::new(),
-            use_injections: Vec::new(),
-            macro_expanded_macro_export_errors: BTreeSet::new(),
-
             arenas,
             dummy_binding: arenas.new_pub_res_binding(Res::Err, DUMMY_SP, LocalExpnId::ROOT),
             builtin_types_bindings: PrimTy::ALL
@@ -1632,8 +1623,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             derive_data: Default::default(),
             local_macro_def_scopes: FxHashMap::default(),
             name_already_seen: FxHashMap::default(),
-            potentially_unused_imports: Vec::new(),
-            potentially_unnecessary_qualifications: Default::default(),
             struct_constructors: Default::default(),
             unused_macros: Default::default(),
             unused_macro_rules: Default::default(),
@@ -1643,16 +1632,13 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             builtin_attrs: Default::default(),
             containers_deriving_copy: Default::default(),
             lint_buffer: LintBuffer::default(),
-            next_node_id: CRATE_NODE_ID,
             node_id_to_def_id,
             disambiguator: DisambiguatorState::new(),
             placeholder_field_indices: Default::default(),
             invocation_parents,
             legacy_const_generic_args: Default::default(),
             item_generics_num_lifetimes: Default::default(),
-            main_def: Default::default(),
             trait_impls: Default::default(),
-            proc_macros: Default::default(),
             confused_type_with_std_module: Default::default(),
             lifetime_elision_allowed: Default::default(),
             stripped_cfg_items: Default::default(),
@@ -1667,6 +1653,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             current_crate_outer_attr_insert_span,
             mods_with_parse_errors: Default::default(),
             impl_trait_names: Default::default(),
+            ..
         };
 
         let root_parent_scope = ParentScope::module(graph_root, resolver.arenas);
diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs
index c59290a757b67..db8b527d59312 100644
--- a/library/core/src/macros/mod.rs
+++ b/library/core/src/macros/mod.rs
@@ -223,13 +223,14 @@ pub macro assert_matches {
 /// }
 /// ```
 ///
-/// The `cfg_select!` macro can also be used in expression position:
+/// The `cfg_select!` macro can also be used in expression position, with or without braces on the
+/// right-hand side:
 ///
 /// ```
 /// #![feature(cfg_select)]
 ///
 /// let _some_string = cfg_select! {
-///     unix => { "With great power comes great electricity bills" }
+///     unix => "With great power comes great electricity bills",
 ///     _ => { "Behind every successful diet is an unwatched pizza" }
 /// };
 /// ```
diff --git a/src/bootstrap/Cargo.lock b/src/bootstrap/Cargo.lock
index 044d360ac3766..537f4b6184f1b 100644
--- a/src/bootstrap/Cargo.lock
+++ b/src/bootstrap/Cargo.lock
@@ -11,21 +11,18 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "ansi_term"
-version = "0.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d52a9bb7ec0cf484c551830a7ce27bd20d67eac647e1befb56b0be4ee39a55d2"
-dependencies = [
- "winapi",
-]
-
 [[package]]
 name = "anstyle"
 version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "55cc3b69f167a1ef2e161439aa98aed94e6028e5f9a59be9a6ffb47aef1651f9"
 
+[[package]]
+name = "autocfg"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
+
 [[package]]
 name = "bitflags"
 version = "2.6.0"
@@ -47,6 +44,7 @@ version = "0.0.0"
 dependencies = [
  "build_helper",
  "cc",
+ "chrono",
  "clap",
  "clap_complete",
  "cmake",
@@ -71,7 +69,6 @@ dependencies = [
  "toml",
  "tracing",
  "tracing-chrome",
- "tracing-forest",
  "tracing-subscriber",
  "walkdir",
  "windows",
@@ -112,6 +109,15 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "chrono"
+version = "0.4.41"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c469d952047f47f91b68d1cba3f10d63c11d73e4636f24f08daf0278abf01c4d"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "clap"
 version = "4.5.20"
@@ -458,6 +464,15 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "objc2-core-foundation"
 version = "0.3.1"
@@ -775,26 +790,6 @@ dependencies = [
  "winapi-util",
 ]
 
-[[package]]
-name = "thiserror"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
-dependencies = [
- "thiserror-impl",
-]
-
-[[package]]
-name = "thiserror-impl"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "thread_local"
 version = "1.1.8"
@@ -857,19 +852,6 @@ dependencies = [
  "valuable",
 ]
 
-[[package]]
-name = "tracing-forest"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee40835db14ddd1e3ba414292272eddde9dad04d3d4b65509656414d1c42592f"
-dependencies = [
- "ansi_term",
- "smallvec",
- "thiserror",
- "tracing",
- "tracing-subscriber",
-]
-
 [[package]]
 name = "tracing-log"
 version = "0.2.0"
diff --git a/src/bootstrap/Cargo.toml b/src/bootstrap/Cargo.toml
index 60d4976b93440..bdf0b42255ee5 100644
--- a/src/bootstrap/Cargo.toml
+++ b/src/bootstrap/Cargo.toml
@@ -7,7 +7,7 @@ default-run = "bootstrap"
 
 [features]
 build-metrics = ["sysinfo"]
-tracing = ["dep:tracing", "dep:tracing-chrome", "dep:tracing-subscriber", "dep:tracing-forest"]
+tracing = ["dep:tracing", "dep:tracing-chrome", "dep:tracing-subscriber", "dep:chrono", "dep:tempfile"]
 
 [lib]
 path = "src/lib.rs"
@@ -61,10 +61,11 @@ xz2 = "0.1"
 sysinfo = { version = "0.37.0", default-features = false, optional = true, features = ["system"] }
 
 # Dependencies needed by the `tracing` feature
+chrono = { version = "0.4", default-features = false, optional = true, features = ["now", "std"] }
 tracing = { version = "0.1", optional = true, features = ["attributes"] }
 tracing-chrome = { version = "0.7", optional = true }
 tracing-subscriber = { version = "0.3", optional = true, features = ["env-filter", "fmt", "registry", "std"] }
-tracing-forest = { version = "0.1.6", optional = true, default-features =  false, features = ["smallvec", "ansi", "env-filter"] }
+tempfile = { version = "3.15.0", optional = true }
 
 [target.'cfg(windows)'.dependencies.junction]
 version = "1.0.0"
diff --git a/src/bootstrap/src/bin/main.rs b/src/bootstrap/src/bin/main.rs
index cf24fedaebb15..8b2d67266a77b 100644
--- a/src/bootstrap/src/bin/main.rs
+++ b/src/bootstrap/src/bin/main.rs
@@ -7,6 +7,7 @@
 
 use std::fs::{self, OpenOptions};
 use std::io::{self, BufRead, BufReader, IsTerminal, Write};
+use std::path::Path;
 use std::str::FromStr;
 use std::time::Instant;
 use std::{env, process};
@@ -15,19 +16,16 @@ use bootstrap::{
     Build, CONFIG_CHANGE_HISTORY, ChangeId, Config, Flags, Subcommand, debug,
     find_recent_config_change_ids, human_readable_changes, t,
 };
-#[cfg(feature = "tracing")]
-use tracing::instrument;
 
-fn is_bootstrap_profiling_enabled() -> bool {
-    env::var("BOOTSTRAP_PROFILE").is_ok_and(|v| v == "1")
+fn is_tracing_enabled() -> bool {
+    cfg!(feature = "tracing")
 }
 
-#[cfg_attr(feature = "tracing", instrument(level = "trace", name = "main"))]
 fn main() {
     #[cfg(feature = "tracing")]
-    let _guard = setup_tracing();
+    let guard = bootstrap::setup_tracing("BOOTSTRAP_TRACING");
 
-    let start_time = Instant::now();
+    let _start_time = Instant::now();
 
     let args = env::args().skip(1).collect::<Vec<_>>();
 
@@ -102,6 +100,35 @@ fn main() {
     let dump_bootstrap_shims = config.dump_bootstrap_shims;
     let out_dir = config.out.clone();
 
+    let tracing_enabled = is_tracing_enabled();
+
+    // Prepare a directory for tracing output
+    // Also store a symlink named "latest" to point to the latest tracing directory.
+    let tracing_dir = out_dir.join("bootstrap-trace").join(std::process::id().to_string());
+    let latest_trace_dir = tracing_dir.parent().unwrap().join("latest");
+    if tracing_enabled {
+        let _ = std::fs::remove_dir_all(&tracing_dir);
+        std::fs::create_dir_all(&tracing_dir).unwrap();
+
+        #[cfg(windows)]
+        let _ = std::fs::remove_dir(&latest_trace_dir);
+        #[cfg(not(windows))]
+        let _ = std::fs::remove_file(&latest_trace_dir);
+
+        #[cfg(not(windows))]
+        fn symlink_dir_inner(original: &Path, link: &Path) -> io::Result<()> {
+            use std::os::unix::fs;
+            fs::symlink(original, link)
+        }
+
+        #[cfg(windows)]
+        fn symlink_dir_inner(target: &Path, junction: &Path) -> io::Result<()> {
+            junction::create(target, junction)
+        }
+
+        t!(symlink_dir_inner(&tracing_dir, &latest_trace_dir));
+    }
+
     debug!("creating new build based on config");
     let mut build = Build::new(config);
     build.build();
@@ -156,12 +183,13 @@ fn main() {
         }
     }
 
-    if is_bootstrap_profiling_enabled() {
-        build.report_summary(start_time);
-    }
-
     #[cfg(feature = "tracing")]
-    build.report_step_graph();
+    {
+        build.report_summary(&tracing_dir.join("command-stats.txt"), _start_time);
+        build.report_step_graph(&tracing_dir);
+        guard.copy_to_dir(&tracing_dir);
+        eprintln!("Tracing/profiling output has been written to {}", latest_trace_dir.display());
+    }
 }
 
 fn check_version(config: &Config) -> Option<String> {
@@ -219,37 +247,3 @@ fn check_version(config: &Config) -> Option<String> {
 
     Some(msg)
 }
-
-// # Note on `tracing` usage in bootstrap
-//
-// Due to the conditional compilation via the `tracing` cargo feature, this means that `tracing`
-// usages in bootstrap need to be also gated behind the `tracing` feature:
-//
-// - `tracing` macros with log levels (`trace!`, `debug!`, `warn!`, `info`, `error`) should not be
-//   used *directly*. You should use the wrapped `tracing` macros which gate the actual invocations
-//   behind `feature = "tracing"`.
-// - `tracing`'s `#[instrument(..)]` macro will need to be gated like `#![cfg_attr(feature =
-//   "tracing", instrument(..))]`.
-#[cfg(feature = "tracing")]
-fn setup_tracing() -> impl Drop {
-    use tracing_forest::ForestLayer;
-    use tracing_subscriber::EnvFilter;
-    use tracing_subscriber::layer::SubscriberExt;
-
-    let filter = EnvFilter::from_env("BOOTSTRAP_TRACING");
-
-    let mut chrome_layer = tracing_chrome::ChromeLayerBuilder::new().include_args(true);
-
-    // Writes the Chrome profile to trace-<unix-timestamp>.json if enabled
-    if !is_bootstrap_profiling_enabled() {
-        chrome_layer = chrome_layer.writer(io::sink());
-    }
-
-    let (chrome_layer, _guard) = chrome_layer.build();
-
-    let registry =
-        tracing_subscriber::registry().with(filter).with(ForestLayer::default()).with(chrome_layer);
-
-    tracing::subscriber::set_global_default(registry).unwrap();
-    _guard
-}
diff --git a/src/bootstrap/src/core/build_steps/check.rs b/src/bootstrap/src/core/build_steps/check.rs
index 6d393446d458e..1e08e8547dc72 100644
--- a/src/bootstrap/src/core/build_steps/check.rs
+++ b/src/bootstrap/src/core/build_steps/check.rs
@@ -172,7 +172,7 @@ impl Rustc {
 
 impl Step for Rustc {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -324,7 +324,7 @@ pub struct CodegenBackend {
 
 impl Step for CodegenBackend {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -410,7 +410,7 @@ macro_rules! tool_check_step {
 
         impl Step for $name {
             type Output = ();
-            const ONLY_HOSTS: bool = true;
+            const IS_HOST: bool = true;
             /// Most of the tool-checks using this macro are run by default.
             const DEFAULT: bool = true $( && $default )?;
 
diff --git a/src/bootstrap/src/core/build_steps/clippy.rs b/src/bootstrap/src/core/build_steps/clippy.rs
index 23d9a032eb909..3c4aa0886c2a5 100644
--- a/src/bootstrap/src/core/build_steps/clippy.rs
+++ b/src/bootstrap/src/core/build_steps/clippy.rs
@@ -256,7 +256,7 @@ impl Rustc {
 
 impl Step for Rustc {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
diff --git a/src/bootstrap/src/core/build_steps/compile.rs b/src/bootstrap/src/core/build_steps/compile.rs
index 2a236de01921e..d860cafa1c0fd 100644
--- a/src/bootstrap/src/core/build_steps/compile.rs
+++ b/src/bootstrap/src/core/build_steps/compile.rs
@@ -16,7 +16,7 @@ use std::{env, fs, str};
 
 use serde_derive::Deserialize;
 #[cfg(feature = "tracing")]
-use tracing::{instrument, span};
+use tracing::span;
 
 use crate::core::build_steps::gcc::{Gcc, GccOutput, add_cg_gcc_cargo_flags};
 use crate::core::build_steps::tool::{RustcPrivateCompilers, SourceType, copy_lld_artifacts};
@@ -104,7 +104,6 @@ impl Step for Std {
         run.crate_or_deps("sysroot").path("library")
     }
 
-    #[cfg_attr(feature = "tracing", instrument(level = "trace", name = "Std::make_run", skip_all))]
     fn make_run(run: RunConfig<'_>) {
         let crates = std_crates_for_run_make(&run);
         let builder = run.builder;
@@ -135,19 +134,6 @@ impl Step for Std {
     /// This will build the standard library for a particular stage of the build
     /// using the `compiler` targeting the `target` architecture. The artifacts
     /// created will also be linked into the sysroot directory.
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "Std::run",
-            skip_all,
-            fields(
-                target = ?self.target,
-                compiler = ?self.compiler,
-                force_recompile = self.force_recompile
-            ),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) {
         let target = self.target;
 
@@ -717,19 +703,6 @@ impl Step for StdLink {
     /// Note that this assumes that `compiler` has already generated the libstd
     /// libraries for `target`, and this method will find them in the relevant
     /// output directory.
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "trace",
-            name = "StdLink::run",
-            skip_all,
-            fields(
-                compiler = ?self.compiler,
-                target_compiler = ?self.target_compiler,
-                target = ?self.target
-            ),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) {
         let compiler = self.compiler;
         let target_compiler = self.target_compiler;
@@ -895,15 +868,6 @@ impl Step for StartupObjects {
     /// They don't require any library support as they're just plain old object
     /// files, so we just use the nightly snapshot compiler to always build them (as
     /// no other compilers are guaranteed to be available).
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "trace",
-            name = "StartupObjects::run",
-            skip_all,
-            fields(compiler = ?self.compiler, target = ?self.target),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> Vec<(PathBuf, DependencyType)> {
         let for_compiler = self.compiler;
         let target = self.target;
@@ -995,7 +959,7 @@ impl Step for Rustc {
     /// uplifting it from stage Y, causing the other stage to fail when attempting to link with
     /// stage X which was never actually built.
     type Output = u32;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -1033,15 +997,6 @@ impl Step for Rustc {
     /// This will build the compiler for a particular stage of the build using
     /// the `build_compiler` targeting the `target` architecture. The artifacts
     /// created will also be linked into the sysroot directory.
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "Rustc::run",
-            skip_all,
-            fields(previous_compiler = ?self.build_compiler, target = ?self.target),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> u32 {
         let build_compiler = self.build_compiler;
         let target = self.target;
@@ -1397,6 +1352,7 @@ pub fn rustc_cargo_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetS
 
     // Build jemalloc on AArch64 with support for page sizes up to 64K
     // See: https://github.com/rust-lang/rust/pull/135081
+    // See also the "JEMALLOC_SYS_WITH_LG_PAGE" setting in the tool build step.
     if builder.config.jemalloc(target)
         && target.starts_with("aarch64")
         && env::var_os("JEMALLOC_SYS_WITH_LG_PAGE").is_none()
@@ -1517,19 +1473,6 @@ impl Step for RustcLink {
     }
 
     /// Same as `std_link`, only for librustc
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "trace",
-            name = "RustcLink::run",
-            skip_all,
-            fields(
-                compiler = ?self.compiler,
-                previous_stage_compiler = ?self.previous_stage_compiler,
-                target = ?self.target,
-            ),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) {
         let compiler = self.compiler;
         let previous_stage_compiler = self.previous_stage_compiler;
@@ -1559,7 +1502,7 @@ pub struct GccCodegenBackend {
 impl Step for GccCodegenBackend {
     type Output = GccCodegenBackendOutput;
 
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("rustc_codegen_gcc").alias("cg_gcc")
@@ -1571,17 +1514,6 @@ impl Step for GccCodegenBackend {
         });
     }
 
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "GccCodegenBackend::run",
-            skip_all,
-            fields(
-                compilers = ?self.compilers,
-            ),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> Self::Output {
         let target = self.compilers.target();
         let build_compiler = self.compilers.build_compiler();
@@ -1644,7 +1576,7 @@ pub struct CraneliftCodegenBackend {
 
 impl Step for CraneliftCodegenBackend {
     type Output = BuildStamp;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("rustc_codegen_cranelift").alias("cg_clif")
@@ -1656,17 +1588,6 @@ impl Step for CraneliftCodegenBackend {
         });
     }
 
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "CraneliftCodegenBackend::run",
-            skip_all,
-            fields(
-                compilers = ?self.compilers,
-            ),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> Self::Output {
         let target = self.compilers.target();
         let build_compiler = self.compilers.build_compiler();
@@ -1841,15 +1762,6 @@ impl Step for Sysroot {
     /// Returns the sysroot that `compiler` is supposed to use.
     /// For the stage0 compiler, this is stage0-sysroot (because of the initial std build).
     /// For all other stages, it's the same stage directory that the compiler lives in.
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "Sysroot::run",
-            skip_all,
-            fields(compiler = ?self.compiler),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> PathBuf {
         let compiler = self.compiler;
         let host_dir = builder.out.join(compiler.host);
@@ -2008,7 +1920,7 @@ pub struct Assemble {
 
 impl Step for Assemble {
     type Output = Compiler;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("compiler/rustc").path("compiler")
@@ -2025,15 +1937,6 @@ impl Step for Assemble {
     /// This will assemble a compiler in `build/$host/stage$stage`. The compiler
     /// must have been previously produced by the `stage - 1` builder.build
     /// compiler.
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "Assemble::run",
-            skip_all,
-            fields(target_compiler = ?self.target_compiler),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> Compiler {
         let target_compiler = self.target_compiler;
 
@@ -2592,7 +2495,7 @@ pub fn stream_cargo(
     let mut cmd = cargo.into_cmd();
 
     #[cfg(feature = "tracing")]
-    let _run_span = crate::trace_cmd!(cmd);
+    let _run_span = crate::utils::tracing::trace_cmd(&cmd);
 
     // Instruct Cargo to give us json messages on stdout, critically leaving
     // stderr as piped so we can get those pretty colors.
diff --git a/src/bootstrap/src/core/build_steps/dist.rs b/src/bootstrap/src/core/build_steps/dist.rs
index 7fdfeabe29d9c..64c2cdd2ec795 100644
--- a/src/bootstrap/src/core/build_steps/dist.rs
+++ b/src/bootstrap/src/core/build_steps/dist.rs
@@ -140,7 +140,7 @@ pub struct RustcDocs {
 impl Step for RustcDocs {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -402,7 +402,7 @@ pub struct Rustc {
 impl Step for Rustc {
     type Output = GeneratedTarball;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("rustc")
@@ -794,7 +794,7 @@ pub struct RustcDev {
 impl Step for RustcDev {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("rustc-dev")
@@ -1024,7 +1024,7 @@ impl Step for Src {
     /// The output path of the src installer tarball
     type Output = GeneratedTarball;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("rust-src")
@@ -1085,7 +1085,7 @@ impl Step for PlainSourceTarball {
     /// Produces the location of the tarball generated
     type Output = GeneratedTarball;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -1233,7 +1233,7 @@ pub struct Cargo {
 impl Step for Cargo {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(run.builder, "cargo");
@@ -1287,7 +1287,7 @@ pub struct RustAnalyzer {
 impl Step for RustAnalyzer {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(run.builder, "rust-analyzer");
@@ -1330,7 +1330,7 @@ pub struct Clippy {
 impl Step for Clippy {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(run.builder, "clippy");
@@ -1378,7 +1378,7 @@ pub struct Miri {
 impl Step for Miri {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(run.builder, "miri");
@@ -1428,7 +1428,7 @@ pub struct CraneliftCodegenBackend {
 impl Step for CraneliftCodegenBackend {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         // We only want to build the cranelift backend in `x dist` if the backend was enabled
@@ -1519,7 +1519,7 @@ pub struct Rustfmt {
 impl Step for Rustfmt {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(run.builder, "rustfmt");
@@ -1564,7 +1564,7 @@ pub struct Extended {
 impl Step for Extended {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -2301,7 +2301,7 @@ pub struct LlvmTools {
 
 impl Step for LlvmTools {
     type Output = Option<GeneratedTarball>;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -2406,7 +2406,7 @@ pub struct LlvmBitcodeLinker {
 impl Step for LlvmBitcodeLinker {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(run.builder, "llvm-bitcode-linker");
@@ -2458,7 +2458,7 @@ pub struct RustDev {
 impl Step for RustDev {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("rust-dev")
@@ -2561,7 +2561,7 @@ pub struct Bootstrap {
 impl Step for Bootstrap {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = false;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("bootstrap")
@@ -2601,7 +2601,7 @@ pub struct BuildManifest {
 impl Step for BuildManifest {
     type Output = GeneratedTarball;
     const DEFAULT: bool = false;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("build-manifest")
@@ -2633,7 +2633,7 @@ pub struct ReproducibleArtifacts {
 impl Step for ReproducibleArtifacts {
     type Output = Option<GeneratedTarball>;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("reproducible-artifacts")
diff --git a/src/bootstrap/src/core/build_steps/doc.rs b/src/bootstrap/src/core/build_steps/doc.rs
index 6f0d5203d1176..f6b27d8312063 100644
--- a/src/bootstrap/src/core/build_steps/doc.rs
+++ b/src/bootstrap/src/core/build_steps/doc.rs
@@ -830,7 +830,7 @@ impl Rustc {
 impl Step for Rustc {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -975,7 +975,7 @@ macro_rules! tool_doc {
         impl Step for $tool {
             type Output = ();
             const DEFAULT: bool = true;
-            const ONLY_HOSTS: bool = true;
+            const IS_HOST: bool = true;
 
             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
                 let builder = run.builder;
@@ -1139,7 +1139,7 @@ pub struct ErrorIndex {
 impl Step for ErrorIndex {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -1181,7 +1181,7 @@ pub struct UnstableBookGen {
 impl Step for UnstableBookGen {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -1248,7 +1248,7 @@ impl RustcBook {
 impl Step for RustcBook {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
diff --git a/src/bootstrap/src/core/build_steps/gcc.rs b/src/bootstrap/src/core/build_steps/gcc.rs
index 389afaecea336..2b36b0f2e2717 100644
--- a/src/bootstrap/src/core/build_steps/gcc.rs
+++ b/src/bootstrap/src/core/build_steps/gcc.rs
@@ -47,7 +47,7 @@ impl GccOutput {
 impl Step for Gcc {
     type Output = GccOutput;
 
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/gcc").alias("gcc")
diff --git a/src/bootstrap/src/core/build_steps/install.rs b/src/bootstrap/src/core/build_steps/install.rs
index 666f2715224e2..4457258e9cdd0 100644
--- a/src/bootstrap/src/core/build_steps/install.rs
+++ b/src/bootstrap/src/core/build_steps/install.rs
@@ -163,7 +163,7 @@ macro_rules! install {
        $($name:ident,
        $condition_name: ident = $path_or_alias: literal,
        $default_cond:expr,
-       only_hosts: $only_hosts:expr,
+       IS_HOST: $IS_HOST:expr,
        $run_item:block $(, $c:ident)*;)+) => {
         $(
             #[derive(Debug, Clone, Hash, PartialEq, Eq)]
@@ -183,7 +183,7 @@ macro_rules! install {
         impl Step for $name {
             type Output = ();
             const DEFAULT: bool = true;
-            const ONLY_HOSTS: bool = $only_hosts;
+            const IS_HOST: bool = $IS_HOST;
             $(const $c: bool = true;)*
 
             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -206,11 +206,11 @@ macro_rules! install {
 }
 
 install!((self, builder, _config),
-    Docs, path = "src/doc", _config.docs, only_hosts: false, {
+    Docs, path = "src/doc", _config.docs, IS_HOST: false, {
         let tarball = builder.ensure(dist::Docs { host: self.target }).expect("missing docs");
         install_sh(builder, "docs", self.compiler.stage, Some(self.target), &tarball);
     };
-    Std, path = "library/std", true, only_hosts: false, {
+    Std, path = "library/std", true, IS_HOST: false, {
         // `expect` should be safe, only None when host != build, but this
         // only runs when host == build
         let tarball = builder.ensure(dist::Std {
@@ -219,13 +219,13 @@ install!((self, builder, _config),
         }).expect("missing std");
         install_sh(builder, "std", self.compiler.stage, Some(self.target), &tarball);
     };
-    Cargo, alias = "cargo", Self::should_build(_config), only_hosts: true, {
+    Cargo, alias = "cargo", Self::should_build(_config), IS_HOST: true, {
         let tarball = builder
             .ensure(dist::Cargo { build_compiler: self.compiler, target: self.target })
             .expect("missing cargo");
         install_sh(builder, "cargo", self.compiler.stage, Some(self.target), &tarball);
     };
-    RustAnalyzer, alias = "rust-analyzer", Self::should_build(_config), only_hosts: true, {
+    RustAnalyzer, alias = "rust-analyzer", Self::should_build(_config), IS_HOST: true, {
         if let Some(tarball) =
             builder.ensure(dist::RustAnalyzer { build_compiler: self.compiler, target: self.target })
         {
@@ -236,13 +236,13 @@ install!((self, builder, _config),
             );
         }
     };
-    Clippy, alias = "clippy", Self::should_build(_config), only_hosts: true, {
+    Clippy, alias = "clippy", Self::should_build(_config), IS_HOST: true, {
         let tarball = builder
             .ensure(dist::Clippy { build_compiler: self.compiler, target: self.target })
             .expect("missing clippy");
         install_sh(builder, "clippy", self.compiler.stage, Some(self.target), &tarball);
     };
-    Miri, alias = "miri", Self::should_build(_config), only_hosts: true, {
+    Miri, alias = "miri", Self::should_build(_config), IS_HOST: true, {
         if let Some(tarball) = builder.ensure(dist::Miri { build_compiler: self.compiler, target: self.target }) {
             install_sh(builder, "miri", self.compiler.stage, Some(self.target), &tarball);
         } else {
@@ -252,7 +252,7 @@ install!((self, builder, _config),
             );
         }
     };
-    LlvmTools, alias = "llvm-tools", _config.llvm_tools_enabled && _config.llvm_enabled(_config.host_target), only_hosts: true, {
+    LlvmTools, alias = "llvm-tools", _config.llvm_tools_enabled && _config.llvm_enabled(_config.host_target), IS_HOST: true, {
         if let Some(tarball) = builder.ensure(dist::LlvmTools { target: self.target }) {
             install_sh(builder, "llvm-tools", self.compiler.stage, Some(self.target), &tarball);
         } else {
@@ -261,7 +261,7 @@ install!((self, builder, _config),
             );
         }
     };
-    Rustfmt, alias = "rustfmt", Self::should_build(_config), only_hosts: true, {
+    Rustfmt, alias = "rustfmt", Self::should_build(_config), IS_HOST: true, {
         if let Some(tarball) = builder.ensure(dist::Rustfmt {
             build_compiler: self.compiler,
             target: self.target
@@ -273,13 +273,13 @@ install!((self, builder, _config),
             );
         }
     };
-    Rustc, path = "compiler/rustc", true, only_hosts: true, {
+    Rustc, path = "compiler/rustc", true, IS_HOST: true, {
         let tarball = builder.ensure(dist::Rustc {
             compiler: builder.compiler(builder.top_stage, self.target),
         });
         install_sh(builder, "rustc", self.compiler.stage, Some(self.target), &tarball);
     };
-    RustcCodegenCranelift, alias = "rustc-codegen-cranelift", Self::should_build(_config), only_hosts: true, {
+    RustcCodegenCranelift, alias = "rustc-codegen-cranelift", Self::should_build(_config), IS_HOST: true, {
         if let Some(tarball) = builder.ensure(dist::CraneliftCodegenBackend {
             build_compiler: self.compiler,
             target: self.target
@@ -292,7 +292,7 @@ install!((self, builder, _config),
             );
         }
     };
-    LlvmBitcodeLinker, alias = "llvm-bitcode-linker", Self::should_build(_config), only_hosts: true, {
+    LlvmBitcodeLinker, alias = "llvm-bitcode-linker", Self::should_build(_config), IS_HOST: true, {
         if let Some(tarball) = builder.ensure(dist::LlvmBitcodeLinker { build_compiler: self.compiler, target: self.target }) {
             install_sh(builder, "llvm-bitcode-linker", self.compiler.stage, Some(self.target), &tarball);
         } else {
@@ -311,7 +311,7 @@ pub struct Src {
 impl Step for Src {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let config = &run.builder.config;
diff --git a/src/bootstrap/src/core/build_steps/llvm.rs b/src/bootstrap/src/core/build_steps/llvm.rs
index 16941a32bb16e..260108292e031 100644
--- a/src/bootstrap/src/core/build_steps/llvm.rs
+++ b/src/bootstrap/src/core/build_steps/llvm.rs
@@ -15,8 +15,6 @@ use std::sync::OnceLock;
 use std::{env, fs};
 
 use build_helper::git::PathFreshness;
-#[cfg(feature = "tracing")]
-use tracing::instrument;
 
 use crate::core::builder::{Builder, RunConfig, ShouldRun, Step, StepMetadata};
 use crate::core::config::{Config, TargetSelection};
@@ -255,7 +253,7 @@ pub struct Llvm {
 impl Step for Llvm {
     type Output = LlvmResult;
 
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/llvm-project").path("src/llvm-project/llvm")
@@ -266,15 +264,6 @@ impl Step for Llvm {
     }
 
     /// Compile LLVM for `target`.
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "Llvm::run",
-            skip_all,
-            fields(target = ?self.target),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> LlvmResult {
         let target = self.target;
         let target_native = if self.target.starts_with("riscv") {
@@ -908,7 +897,7 @@ pub struct Enzyme {
 
 impl Step for Enzyme {
     type Output = PathBuf;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/enzyme/enzyme")
@@ -919,15 +908,6 @@ impl Step for Enzyme {
     }
 
     /// Compile Enzyme for `target`.
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "Enzyme::run",
-            skip_all,
-            fields(target = ?self.target),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> PathBuf {
         builder.require_submodule(
             "src/tools/enzyme",
@@ -1013,7 +993,7 @@ pub struct Lld {
 
 impl Step for Lld {
     type Output = PathBuf;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/llvm-project/lld")
diff --git a/src/bootstrap/src/core/build_steps/run.rs b/src/bootstrap/src/core/build_steps/run.rs
index 962dd372849d2..7f1a7d0025742 100644
--- a/src/bootstrap/src/core/build_steps/run.rs
+++ b/src/bootstrap/src/core/build_steps/run.rs
@@ -22,7 +22,7 @@ pub struct BuildManifest;
 
 impl Step for BuildManifest {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/build-manifest")
@@ -61,7 +61,7 @@ pub struct BumpStage0;
 
 impl Step for BumpStage0 {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/bump-stage0")
@@ -83,7 +83,7 @@ pub struct ReplaceVersionPlaceholder;
 
 impl Step for ReplaceVersionPlaceholder {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/replace-version-placeholder")
@@ -107,7 +107,6 @@ pub struct Miri {
 
 impl Step for Miri {
     type Output = ();
-    const ONLY_HOSTS: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/miri")
@@ -175,7 +174,7 @@ pub struct CollectLicenseMetadata;
 
 impl Step for CollectLicenseMetadata {
     type Output = PathBuf;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/collect-license-metadata")
@@ -206,7 +205,7 @@ pub struct GenerateCopyright;
 
 impl Step for GenerateCopyright {
     type Output = Vec<PathBuf>;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/generate-copyright")
@@ -270,7 +269,7 @@ pub struct GenerateWindowsSys;
 
 impl Step for GenerateWindowsSys {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/generate-windows-sys")
@@ -332,7 +331,7 @@ pub struct UnicodeTableGenerator;
 
 impl Step for UnicodeTableGenerator {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/unicode-table-generator")
@@ -354,7 +353,7 @@ pub struct FeaturesStatusDump;
 
 impl Step for FeaturesStatusDump {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/features-status-dump")
@@ -416,7 +415,7 @@ impl Step for CoverageDump {
     type Output = ();
 
     const DEFAULT: bool = false;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/coverage-dump")
@@ -438,7 +437,7 @@ pub struct Rustfmt;
 
 impl Step for Rustfmt {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/rustfmt")
diff --git a/src/bootstrap/src/core/build_steps/synthetic_targets.rs b/src/bootstrap/src/core/build_steps/synthetic_targets.rs
index 477ff9553a480..21733c5d9e3f7 100644
--- a/src/bootstrap/src/core/build_steps/synthetic_targets.rs
+++ b/src/bootstrap/src/core/build_steps/synthetic_targets.rs
@@ -21,7 +21,6 @@ pub(crate) struct MirOptPanicAbortSyntheticTarget {
 impl Step for MirOptPanicAbortSyntheticTarget {
     type Output = TargetSelection;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.never()
diff --git a/src/bootstrap/src/core/build_steps/test.rs b/src/bootstrap/src/core/build_steps/test.rs
index f1be0af31837b..4006bed4ac524 100644
--- a/src/bootstrap/src/core/build_steps/test.rs
+++ b/src/bootstrap/src/core/build_steps/test.rs
@@ -10,8 +10,6 @@ use std::path::{Path, PathBuf};
 use std::{env, fs, iter};
 
 use build_helper::exit;
-#[cfg(feature = "tracing")]
-use tracing::instrument;
 
 use crate::core::build_steps::compile::{Std, run_cargo};
 use crate::core::build_steps::doc::DocumentationFormat;
@@ -51,7 +49,7 @@ pub struct CrateBootstrap {
 
 impl Step for CrateBootstrap {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -109,7 +107,7 @@ pub struct Linkcheck {
 
 impl Step for Linkcheck {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     /// Runs the `linkchecker` tool as compiled in `stage` by the `host` compiler.
@@ -189,7 +187,7 @@ pub struct HtmlCheck {
 impl Step for HtmlCheck {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -236,7 +234,7 @@ pub struct Cargotest {
 
 impl Step for Cargotest {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/cargotest")
@@ -313,7 +311,7 @@ impl Cargo {
 
 impl Step for Cargo {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path(Self::CRATE_PATH)
@@ -410,7 +408,7 @@ pub struct RustAnalyzer {
 
 impl Step for RustAnalyzer {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -469,7 +467,7 @@ pub struct Rustfmt {
 
 impl Step for Rustfmt {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/rustfmt")
@@ -561,7 +559,6 @@ impl Miri {
 
 impl Step for Miri {
     type Output = ();
-    const ONLY_HOSTS: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/miri")
@@ -681,7 +678,6 @@ pub struct CargoMiri {
 
 impl Step for CargoMiri {
     type Output = ();
-    const ONLY_HOSTS: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/miri/cargo-miri")
@@ -760,10 +756,6 @@ impl Step for CompiletestTest {
     }
 
     /// Runs `cargo test` for compiletest.
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(level = "debug", name = "CompiletestTest::run", skip_all)
-    )]
     fn run(self, builder: &Builder<'_>) {
         let host = self.host;
 
@@ -811,7 +803,7 @@ pub struct Clippy {
 
 impl Step for Clippy {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -911,7 +903,7 @@ pub struct RustdocTheme {
 impl Step for RustdocTheme {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/rustdoc-themes")
@@ -948,7 +940,7 @@ pub struct RustdocJSStd {
 impl Step for RustdocJSStd {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = run.builder.config.nodejs.is_some();
@@ -1008,7 +1000,7 @@ pub struct RustdocJSNotStd {
 impl Step for RustdocJSNotStd {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = run.builder.config.nodejs.is_some();
@@ -1063,7 +1055,7 @@ pub struct RustdocGUI {
 impl Step for RustdocGUI {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -1156,7 +1148,7 @@ pub struct Tidy;
 impl Step for Tidy {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     /// Runs the `tidy` tool.
     ///
@@ -1274,7 +1266,7 @@ macro_rules! test {
             mode: $mode:expr,
             suite: $suite:expr,
             default: $default:expr
-            $( , only_hosts: $only_hosts:expr )? // default: false
+            $( , IS_HOST: $IS_HOST:expr )? // default: false
             $( , compare_mode: $compare_mode:expr )? // default: None
             $( , )? // optional trailing comma
         }
@@ -1289,10 +1281,10 @@ macro_rules! test {
         impl Step for $name {
             type Output = ();
             const DEFAULT: bool = $default;
-            const ONLY_HOSTS: bool = (const {
+            const IS_HOST: bool = (const {
                 #[allow(unused_assignments, unused_mut)]
                 let mut value = false;
-                $( value = $only_hosts; )?
+                $( value = $IS_HOST; )?
                 value
             });
 
@@ -1340,7 +1332,7 @@ pub struct CrateRunMakeSupport {
 
 impl Step for CrateRunMakeSupport {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/run-make-support")
@@ -1377,7 +1369,7 @@ pub struct CrateBuildHelper {
 
 impl Step for CrateBuildHelper {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/build_helper")
@@ -1445,7 +1437,7 @@ test!(UiFullDeps {
     mode: "ui",
     suite: "ui-fulldeps",
     default: true,
-    only_hosts: true,
+    IS_HOST: true,
 });
 
 test!(Rustdoc {
@@ -1453,14 +1445,14 @@ test!(Rustdoc {
     mode: "rustdoc",
     suite: "rustdoc",
     default: true,
-    only_hosts: true,
+    IS_HOST: true,
 });
 test!(RustdocUi {
     path: "tests/rustdoc-ui",
     mode: "ui",
     suite: "rustdoc-ui",
     default: true,
-    only_hosts: true,
+    IS_HOST: true,
 });
 
 test!(RustdocJson {
@@ -1468,7 +1460,7 @@ test!(RustdocJson {
     mode: "rustdoc-json",
     suite: "rustdoc-json",
     default: true,
-    only_hosts: true,
+    IS_HOST: true,
 });
 
 test!(Pretty {
@@ -1476,7 +1468,7 @@ test!(Pretty {
     mode: "pretty",
     suite: "pretty",
     default: true,
-    only_hosts: true,
+    IS_HOST: true,
 });
 
 test!(RunMake { path: "tests/run-make", mode: "run-make", suite: "run-make", default: true });
@@ -1507,7 +1499,7 @@ impl Step for Coverage {
     type Output = ();
     const DEFAULT: bool = true;
     /// Compiletest will automatically skip the "coverage-run" tests if necessary.
-    const ONLY_HOSTS: bool = false;
+    const IS_HOST: bool = false;
 
     fn should_run(mut run: ShouldRun<'_>) -> ShouldRun<'_> {
         // Support various invocation styles, including:
@@ -1586,7 +1578,7 @@ test!(CoverageRunRustdoc {
     mode: "coverage-run",
     suite: "coverage-run-rustdoc",
     default: true,
-    only_hosts: true,
+    IS_HOST: true,
 });
 
 // For the mir-opt suite we do not use macros, as we need custom behavior when blessing.
@@ -1599,7 +1591,6 @@ pub struct MirOpt {
 impl Step for MirOpt {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.suite_path("tests/mir-opt")
@@ -2276,7 +2267,7 @@ struct BookTest {
 
 impl Step for BookTest {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.never()
@@ -2442,7 +2433,7 @@ macro_rules! test_book {
             impl Step for $name {
                 type Output = ();
                 const DEFAULT: bool = $default;
-                const ONLY_HOSTS: bool = true;
+                const IS_HOST: bool = true;
 
                 fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
                     run.path($path)
@@ -2502,7 +2493,7 @@ pub struct ErrorIndex {
 impl Step for ErrorIndex {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         // Also add `error-index` here since that is what appears in the error message
@@ -2598,7 +2589,7 @@ pub struct CrateLibrustc {
 impl Step for CrateLibrustc {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.crate_or_deps("rustc-main").path("compiler")
@@ -2883,7 +2874,7 @@ pub struct CrateRustdoc {
 impl Step for CrateRustdoc {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.paths(&["src/librustdoc", "src/tools/rustdoc"])
@@ -2975,7 +2966,7 @@ pub struct CrateRustdocJsonTypes {
 impl Step for CrateRustdocJsonTypes {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/rustdoc-json-types")
@@ -3164,7 +3155,7 @@ pub struct Bootstrap;
 impl Step for Bootstrap {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     /// Tests the build system itself.
     fn run(self, builder: &Builder<'_>) {
@@ -3234,7 +3225,7 @@ pub struct TierCheck {
 impl Step for TierCheck {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/tier-check")
@@ -3288,7 +3279,7 @@ pub struct LintDocs {
 impl Step for LintDocs {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/lint-docs")
@@ -3314,7 +3305,7 @@ pub struct RustInstaller;
 
 impl Step for RustInstaller {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     /// Ensure the version placeholder replacement tool builds
@@ -3434,7 +3425,7 @@ pub struct CodegenCranelift {
 impl Step for CodegenCranelift {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.paths(&["compiler/rustc_codegen_cranelift"])
@@ -3562,7 +3553,7 @@ pub struct CodegenGCC {
 impl Step for CodegenGCC {
     type Output = ();
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.paths(&["compiler/rustc_codegen_gcc"])
@@ -3695,7 +3686,7 @@ pub struct TestFloatParse {
 
 impl Step for TestFloatParse {
     type Output = ();
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -3761,7 +3752,7 @@ pub struct CollectLicenseMetadata;
 
 impl Step for CollectLicenseMetadata {
     type Output = PathBuf;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/collect-license-metadata")
diff --git a/src/bootstrap/src/core/build_steps/tool.rs b/src/bootstrap/src/core/build_steps/tool.rs
index 793e6b629c991..b62c9a906b79c 100644
--- a/src/bootstrap/src/core/build_steps/tool.rs
+++ b/src/bootstrap/src/core/build_steps/tool.rs
@@ -13,9 +13,6 @@ use std::ffi::OsStr;
 use std::path::PathBuf;
 use std::{env, fs};
 
-#[cfg(feature = "tracing")]
-use tracing::instrument;
-
 use crate::core::build_steps::compile::is_lto_stage;
 use crate::core::build_steps::toolstate::ToolState;
 use crate::core::build_steps::{compile, llvm};
@@ -229,6 +226,14 @@ pub fn prepare_tool_cargo(
     // own copy
     cargo.env("LZMA_API_STATIC", "1");
 
+    // Build jemalloc on AArch64 with support for page sizes up to 64K
+    // See: https://github.com/rust-lang/rust/pull/135081
+    // Note that `miri` always uses jemalloc. As such, there is no checking of the jemalloc build flag.
+    // See also the "JEMALLOC_SYS_WITH_LG_PAGE" setting in the compile build step.
+    if target.starts_with("aarch64") && env::var_os("JEMALLOC_SYS_WITH_LG_PAGE").is_none() {
+        cargo.env("JEMALLOC_SYS_WITH_LG_PAGE", "16");
+    }
+
     // CFG_RELEASE is needed by rustfmt (and possibly other tools) which
     // import rustc-ap-rustc_attr which requires this to be set for the
     // `#[cfg(version(...))]` attribute.
@@ -415,14 +420,6 @@ macro_rules! bootstrap_tool {
                 });
             }
 
-            #[cfg_attr(
-                feature = "tracing",
-                instrument(
-                    level = "debug",
-                    name = $tool_name,
-                    skip_all,
-                ),
-            )]
             fn run(self, builder: &Builder<'_>) -> ToolBuildResult {
                 $(
                     for submodule in $submodules {
@@ -687,7 +684,7 @@ impl Step for Rustdoc {
     type Output = PathBuf;
 
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/rustdoc").path("src/librustdoc")
@@ -809,7 +806,7 @@ impl Cargo {
 impl Step for Cargo {
     type Output = ToolBuildResult;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -885,7 +882,7 @@ impl LldWrapper {
 impl Step for LldWrapper {
     type Output = BuiltLldWrapper;
 
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/lld-wrapper")
@@ -901,15 +898,6 @@ impl Step for LldWrapper {
         });
     }
 
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "LldWrapper::run",
-            skip_all,
-            fields(build_compiler = ?self.build_compiler),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> Self::Output {
         let lld_dir = builder.ensure(llvm::Lld { target: self.target });
         let tool = builder.ensure(ToolBuild {
@@ -986,7 +974,7 @@ impl WasmComponentLd {
 impl Step for WasmComponentLd {
     type Output = ToolBuildResult;
 
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.path("src/tools/wasm-component-ld")
@@ -1002,15 +990,6 @@ impl Step for WasmComponentLd {
         });
     }
 
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "debug",
-            name = "WasmComponentLd::run",
-            skip_all,
-            fields(build_compiler = ?self.build_compiler),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> ToolBuildResult {
         builder.ensure(ToolBuild {
             build_compiler: self.build_compiler,
@@ -1049,7 +1028,7 @@ impl RustAnalyzer {
 impl Step for RustAnalyzer {
     type Output = ToolBuildResult;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -1102,7 +1081,7 @@ impl Step for RustAnalyzerProcMacroSrv {
     type Output = ToolBuildResult;
 
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -1192,7 +1171,7 @@ impl LlvmBitcodeLinker {
 impl Step for LlvmBitcodeLinker {
     type Output = ToolBuildResult;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
@@ -1207,10 +1186,6 @@ impl Step for LlvmBitcodeLinker {
         });
     }
 
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(level = "debug", name = "LlvmBitcodeLinker::run", skip_all)
-    )]
     fn run(self, builder: &Builder<'_>) -> ToolBuildResult {
         builder.ensure(ToolBuild {
             build_compiler: self.build_compiler,
@@ -1246,7 +1221,7 @@ pub enum LibcxxVersion {
 impl Step for LibcxxVersionTool {
     type Output = LibcxxVersion;
     const DEFAULT: bool = false;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.never()
@@ -1407,7 +1382,7 @@ macro_rules! tool_rustc_extended {
         impl Step for $name {
             type Output = ToolBuildResult;
             const DEFAULT: bool = true; // Overridden by `should_run_tool_build_step`
-            const ONLY_HOSTS: bool = true;
+            const IS_HOST: bool = true;
 
             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
                 should_run_extended_rustc_tool(
@@ -1575,7 +1550,7 @@ impl TestFloatParse {
 
 impl Step for TestFloatParse {
     type Output = ToolBuildResult;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
     const DEFAULT: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
diff --git a/src/bootstrap/src/core/build_steps/vendor.rs b/src/bootstrap/src/core/build_steps/vendor.rs
index 0caeb328811aa..7b860ceb94325 100644
--- a/src/bootstrap/src/core/build_steps/vendor.rs
+++ b/src/bootstrap/src/core/build_steps/vendor.rs
@@ -53,7 +53,7 @@ pub(crate) struct Vendor {
 impl Step for Vendor {
     type Output = VendorOutput;
     const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
+    const IS_HOST: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         run.alias("placeholder").default_condition(true)
diff --git a/src/bootstrap/src/core/builder/cargo.rs b/src/bootstrap/src/core/builder/cargo.rs
index 757b9277ec65d..3ce21eb151c3c 100644
--- a/src/bootstrap/src/core/builder/cargo.rs
+++ b/src/bootstrap/src/core/builder/cargo.rs
@@ -499,6 +499,10 @@ impl Builder<'_> {
             build_stamp::clear_if_dirty(self, &out_dir, &backend);
         }
 
+        if self.config.cmd.timings() {
+            cargo.arg("--timings");
+        }
+
         if cmd_kind == Kind::Doc {
             let my_out = match mode {
                 // This is the intended out directory for compiler documentation.
diff --git a/src/bootstrap/src/core/builder/mod.rs b/src/bootstrap/src/core/builder/mod.rs
index 54bf1842ab31b..6226c81a3fdb7 100644
--- a/src/bootstrap/src/core/builder/mod.rs
+++ b/src/bootstrap/src/core/builder/mod.rs
@@ -100,8 +100,13 @@ pub trait Step: 'static + Clone + Debug + PartialEq + Eq + Hash {
     /// by `Step::should_run`.
     const DEFAULT: bool = false;
 
-    /// If true, then this rule should be skipped if --target was specified, but --host was not
-    const ONLY_HOSTS: bool = false;
+    /// If this value is true, then the values of `run.target` passed to the `make_run` function of
+    /// this Step will be determined based on the `--host` flag.
+    /// If this value is false, then they will be determined based on the `--target` flag.
+    ///
+    /// A corollary of the above is that if this is set to true, then the step will be skipped if
+    /// `--target` was specified, but `--host` was explicitly set to '' (empty string).
+    const IS_HOST: bool = false;
 
     /// Primary function to implement `Step` logic.
     ///
@@ -298,7 +303,7 @@ pub fn crate_description(crates: &[impl AsRef<str>]) -> String {
 
 struct StepDescription {
     default: bool,
-    only_hosts: bool,
+    is_host: bool,
     should_run: fn(ShouldRun<'_>) -> ShouldRun<'_>,
     make_run: fn(RunConfig<'_>),
     name: &'static str,
@@ -500,7 +505,7 @@ impl StepDescription {
     fn from<S: Step>(kind: Kind) -> StepDescription {
         StepDescription {
             default: S::DEFAULT,
-            only_hosts: S::ONLY_HOSTS,
+            is_host: S::IS_HOST,
             should_run: S::should_run,
             make_run: S::make_run,
             name: std::any::type_name::<S>(),
@@ -516,7 +521,7 @@ impl StepDescription {
         }
 
         // Determine the targets participating in this rule.
-        let targets = if self.only_hosts { &builder.hosts } else { &builder.targets };
+        let targets = if self.is_host { &builder.hosts } else { &builder.targets };
 
         for target in targets {
             let run = RunConfig { builder, paths: pathsets.clone(), target: *target };
@@ -951,6 +956,9 @@ impl Step for Libdir {
     }
 }
 
+#[cfg(feature = "tracing")]
+pub const STEP_SPAN_TARGET: &str = "STEP";
+
 impl<'a> Builder<'a> {
     fn get_step_descriptions(kind: Kind) -> Vec<StepDescription> {
         macro_rules! describe {
@@ -1271,7 +1279,7 @@ impl<'a> Builder<'a> {
     pub fn new(build: &Build) -> Builder<'_> {
         let paths = &build.config.paths;
         let (kind, paths) = match build.config.cmd {
-            Subcommand::Build => (Kind::Build, &paths[..]),
+            Subcommand::Build { .. } => (Kind::Build, &paths[..]),
             Subcommand::Check { .. } => (Kind::Check, &paths[..]),
             Subcommand::Clippy { .. } => (Kind::Clippy, &paths[..]),
             Subcommand::Fix => (Kind::Fix, &paths[..]),
@@ -1680,8 +1688,6 @@ You have to build a stage1 compiler for `{}` first, and then use it to build a s
                 panic!("{}", out);
             }
             if let Some(out) = self.cache.get(&step) {
-                self.verbose_than(1, || println!("{}c {:?}", "  ".repeat(stack.len()), step));
-
                 #[cfg(feature = "tracing")]
                 {
                     if let Some(parent) = stack.last() {
@@ -1691,7 +1697,6 @@ You have to build a stage1 compiler for `{}` first, and then use it to build a s
                 }
                 return out;
             }
-            self.verbose_than(1, || println!("{}> {:?}", "  ".repeat(stack.len()), step));
 
             #[cfg(feature = "tracing")]
             {
@@ -1706,10 +1711,29 @@ You have to build a stage1 compiler for `{}` first, and then use it to build a s
         #[cfg(feature = "build-metrics")]
         self.metrics.enter_step(&step, self);
 
+        if self.config.print_step_timings && !self.config.dry_run() {
+            println!("[TIMING:start] {}", pretty_print_step(&step));
+        }
+
         let (out, dur) = {
             let start = Instant::now();
             let zero = Duration::new(0, 0);
             let parent = self.time_spent_on_dependencies.replace(zero);
+
+            #[cfg(feature = "tracing")]
+            let _span = {
+                // Keep the target and field names synchronized with `setup_tracing`.
+                let span = tracing::info_span!(
+                    target: STEP_SPAN_TARGET,
+                    // We cannot use a dynamic name here, so instead we record the actual step name
+                    // in the step_name field.
+                    "step",
+                    step_name = pretty_step_name::<S>(),
+                    args = step_debug_args(&step)
+                );
+                span.entered()
+            };
+
             let out = step.clone().run(self);
             let dur = start.elapsed();
             let deps = self.time_spent_on_dependencies.replace(parent + dur);
@@ -1717,13 +1741,9 @@ You have to build a stage1 compiler for `{}` first, and then use it to build a s
         };
 
         if self.config.print_step_timings && !self.config.dry_run() {
-            let step_string = format!("{step:?}");
-            let brace_index = step_string.find('{').unwrap_or(0);
-            let type_string = type_name::<S>();
             println!(
-                "[TIMING] {} {} -- {}.{:03}",
-                &type_string.strip_prefix("bootstrap::").unwrap_or(type_string),
-                &step_string[brace_index..],
+                "[TIMING:end] {} -- {}.{:03}",
+                pretty_print_step(&step),
                 dur.as_secs(),
                 dur.subsec_millis()
             );
@@ -1737,7 +1757,6 @@ You have to build a stage1 compiler for `{}` first, and then use it to build a s
             let cur_step = stack.pop().expect("step stack empty");
             assert_eq!(cur_step.downcast_ref(), Some(&step));
         }
-        self.verbose_than(1, || println!("{}< {:?}", "  ".repeat(self.stack.borrow().len()), step));
         self.cache.put(step, out.clone());
         out
     }
@@ -1810,6 +1829,25 @@ You have to build a stage1 compiler for `{}` first, and then use it to build a s
     }
 }
 
+/// Return qualified step name, e.g. `compile::Rustc`.
+pub fn pretty_step_name<S: Step>() -> String {
+    // Normalize step type path to only keep the module and the type name
+    let path = type_name::<S>().rsplit("::").take(2).collect::<Vec<_>>();
+    path.into_iter().rev().collect::<Vec<_>>().join("::")
+}
+
+/// Renders `step` using its `Debug` implementation and extract the field arguments out of it.
+fn step_debug_args<S: Step>(step: &S) -> String {
+    let step_dbg_repr = format!("{step:?}");
+    let brace_start = step_dbg_repr.find('{').unwrap_or(0);
+    let brace_end = step_dbg_repr.rfind('}').unwrap_or(step_dbg_repr.len());
+    step_dbg_repr[brace_start + 1..brace_end - 1].trim().to_string()
+}
+
+fn pretty_print_step<S: Step>(step: &S) -> String {
+    format!("{} {{ {} }}", pretty_step_name::<S>(), step_debug_args(step))
+}
+
 impl<'a> AsRef<ExecutionContext> for Builder<'a> {
     fn as_ref(&self) -> &ExecutionContext {
         self.exec_ctx()
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index 9ced81e1e283d..5eea54360238d 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -1342,7 +1342,7 @@ impl Config {
             Subcommand::Doc { .. } => {
                 flags_stage.or(build_doc_stage).unwrap_or(if download_rustc { 2 } else { 1 })
             }
-            Subcommand::Build => {
+            Subcommand::Build { .. } => {
                 flags_stage.or(build_build_stage).unwrap_or(if download_rustc { 2 } else { 1 })
             }
             Subcommand::Test { .. } | Subcommand::Miri { .. } => {
@@ -1363,7 +1363,7 @@ impl Config {
 
         // Now check that the selected stage makes sense, and if not, print a warning and end
         match (config.stage, &config.cmd) {
-            (0, Subcommand::Build) => {
+            (0, Subcommand::Build { .. }) => {
                 eprintln!("ERROR: cannot build anything on stage 0. Use at least stage 1.");
                 exit!(1);
             }
@@ -1396,7 +1396,7 @@ impl Config {
                 Subcommand::Test { .. }
                 | Subcommand::Miri { .. }
                 | Subcommand::Doc { .. }
-                | Subcommand::Build
+                | Subcommand::Build { .. }
                 | Subcommand::Bench { .. }
                 | Subcommand::Dist
                 | Subcommand::Install => {
diff --git a/src/bootstrap/src/core/config/flags.rs b/src/bootstrap/src/core/config/flags.rs
index 31a427f9ffaac..17bfb388280a9 100644
--- a/src/bootstrap/src/core/config/flags.rs
+++ b/src/bootstrap/src/core/config/flags.rs
@@ -241,7 +241,7 @@ fn normalize_args(args: &[String]) -> Vec<String> {
     it.collect()
 }
 
-#[derive(Debug, Clone, Default, clap::Subcommand)]
+#[derive(Debug, Clone, clap::Subcommand)]
 pub enum Subcommand {
     #[command(aliases = ["b"], long_about = "\n
     Arguments:
@@ -256,8 +256,11 @@ pub enum Subcommand {
             ./x.py build --stage 0
             ./x.py build ")]
     /// Compile either the compiler or libraries
-    #[default]
-    Build,
+    Build {
+        #[arg(long)]
+        /// Pass `--timings` to Cargo to get crate build timings
+        timings: bool,
+    },
     #[command(aliases = ["c"], long_about = "\n
     Arguments:
         This subcommand accepts a number of paths to directories to the crates
@@ -269,6 +272,9 @@ pub enum Subcommand {
         #[arg(long)]
         /// Check all targets
         all_targets: bool,
+        #[arg(long)]
+        /// Pass `--timings` to Cargo to get crate build timings
+        timings: bool,
     },
     /// Run Clippy (uses rustup/cargo-installed clippy binary)
     #[command(long_about = "\n
@@ -494,11 +500,17 @@ Arguments:
     Perf(PerfArgs),
 }
 
+impl Default for Subcommand {
+    fn default() -> Self {
+        Subcommand::Build { timings: false }
+    }
+}
+
 impl Subcommand {
     pub fn kind(&self) -> Kind {
         match self {
             Subcommand::Bench { .. } => Kind::Bench,
-            Subcommand::Build => Kind::Build,
+            Subcommand::Build { .. } => Kind::Build,
             Subcommand::Check { .. } => Kind::Check,
             Subcommand::Clippy { .. } => Kind::Clippy,
             Subcommand::Doc { .. } => Kind::Doc,
@@ -626,6 +638,13 @@ impl Subcommand {
         }
     }
 
+    pub fn timings(&self) -> bool {
+        match *self {
+            Subcommand::Build { timings, .. } | Subcommand::Check { timings, .. } => timings,
+            _ => false,
+        }
+    }
+
     pub fn vendor_versioned_dirs(&self) -> bool {
         match *self {
             Subcommand::Vendor { versioned_dirs, .. } => versioned_dirs,
diff --git a/src/bootstrap/src/lib.rs b/src/bootstrap/src/lib.rs
index 0b65ebc067189..706a3cbb2109b 100644
--- a/src/bootstrap/src/lib.rs
+++ b/src/bootstrap/src/lib.rs
@@ -37,14 +37,14 @@ use crate::core::builder;
 use crate::core::builder::Kind;
 use crate::core::config::{DryRun, LldMode, LlvmLibunwind, TargetSelection, flags};
 use crate::utils::exec::{BootstrapCommand, command};
-use crate::utils::helpers::{
-    self, dir_is_empty, exe, libdir, set_file_times, split_debuginfo, symlink_dir,
-};
+use crate::utils::helpers::{self, dir_is_empty, exe, libdir, set_file_times, split_debuginfo};
 
 mod core;
 mod utils;
 
 pub use core::builder::PathSet;
+#[cfg(feature = "tracing")]
+pub use core::builder::STEP_SPAN_TARGET;
 pub use core::config::flags::{Flags, Subcommand};
 pub use core::config::{ChangeId, Config};
 
@@ -53,7 +53,9 @@ use tracing::{instrument, span};
 pub use utils::change_tracker::{
     CONFIG_CHANGE_HISTORY, find_recent_config_change_ids, human_readable_changes,
 };
-pub use utils::helpers::PanicTracker;
+pub use utils::helpers::{PanicTracker, symlink_dir};
+#[cfg(feature = "tracing")]
+pub use utils::tracing::setup_tracing;
 
 use crate::core::build_steps::vendor::VENDOR_DIR;
 
@@ -2005,13 +2007,13 @@ to download LLVM rather than building it.
         &self.config.exec_ctx
     }
 
-    pub fn report_summary(&self, start_time: Instant) {
-        self.config.exec_ctx.profiler().report_summary(start_time);
+    pub fn report_summary(&self, path: &Path, start_time: Instant) {
+        self.config.exec_ctx.profiler().report_summary(path, start_time);
     }
 
     #[cfg(feature = "tracing")]
-    pub fn report_step_graph(self) {
-        self.step_graph.into_inner().store_to_dot_files();
+    pub fn report_step_graph(self, directory: &Path) {
+        self.step_graph.into_inner().store_to_dot_files(directory);
     }
 }
 
diff --git a/src/bootstrap/src/utils/exec.rs b/src/bootstrap/src/utils/exec.rs
index 03760faec690b..9a536f75ab741 100644
--- a/src/bootstrap/src/utils/exec.rs
+++ b/src/bootstrap/src/utils/exec.rs
@@ -15,7 +15,6 @@ use std::hash::Hash;
 use std::io::{BufWriter, Write};
 use std::panic::Location;
 use std::path::Path;
-use std::process;
 use std::process::{
     Child, ChildStderr, ChildStdout, Command, CommandArgs, CommandEnvs, ExitStatus, Output, Stdio,
 };
@@ -26,10 +25,8 @@ use build_helper::ci::CiEnv;
 use build_helper::drop_bomb::DropBomb;
 use build_helper::exit;
 
-use crate::PathBuf;
 use crate::core::config::DryRun;
-#[cfg(feature = "tracing")]
-use crate::trace_cmd;
+use crate::{PathBuf, t};
 
 /// What should be done when the command fails.
 #[derive(Debug, Copy, Clone)]
@@ -77,9 +74,17 @@ pub struct CommandFingerprint {
 }
 
 impl CommandFingerprint {
+    #[cfg(feature = "tracing")]
+    pub(crate) fn program_name(&self) -> String {
+        Path::new(&self.program)
+            .file_name()
+            .map(|p| p.to_string_lossy().to_string())
+            .unwrap_or_else(|| "<unknown command>".to_string())
+    }
+
     /// Helper method to format both Command and BootstrapCommand as a short execution line,
     /// without all the other details (e.g. environment variables).
-    pub fn format_short_cmd(&self) -> String {
+    pub(crate) fn format_short_cmd(&self) -> String {
         use std::fmt::Write;
 
         let mut cmd = self.program.to_string_lossy().to_string();
@@ -121,17 +126,9 @@ impl CommandProfiler {
         entry.traces.push(ExecutionTrace::CacheHit);
     }
 
-    pub fn report_summary(&self, start_time: Instant) {
-        let pid = process::id();
-        let filename = format!("bootstrap-profile-{pid}.txt");
-
-        let file = match File::create(&filename) {
-            Ok(f) => f,
-            Err(e) => {
-                eprintln!("Failed to create profiler output file: {e}");
-                return;
-            }
-        };
+    /// Report summary of executed commands file at the specified `path`.
+    pub fn report_summary(&self, path: &Path, start_time: Instant) {
+        let file = t!(File::create(path));
 
         let mut writer = BufWriter::new(file);
         let stats = self.stats.lock().unwrap();
@@ -221,8 +218,6 @@ impl CommandProfiler {
         writeln!(writer, "Total cache hits: {total_cache_hits}").unwrap();
         writeln!(writer, "Estimated time saved due to cache hits: {total_saved_duration:.2?}")
             .unwrap();
-
-        println!("Command profiler report saved to {filename}");
     }
 }
 
@@ -686,9 +681,6 @@ impl ExecutionContext {
     ) -> DeferredCommand<'a> {
         let fingerprint = command.fingerprint();
 
-        #[cfg(feature = "tracing")]
-        let span_guard = trace_cmd!(command);
-
         if let Some(cached_output) = self.command_cache.get(&fingerprint) {
             command.mark_as_executed();
             self.verbose(|| println!("Cache hit: {command:?}"));
@@ -696,6 +688,9 @@ impl ExecutionContext {
             return DeferredCommand { state: CommandState::Cached(cached_output) };
         }
 
+        #[cfg(feature = "tracing")]
+        let span_guard = crate::utils::tracing::trace_cmd(command);
+
         let created_at = command.get_created_location();
         let executed_at = std::panic::Location::caller();
 
@@ -779,7 +774,7 @@ impl ExecutionContext {
         }
 
         #[cfg(feature = "tracing")]
-        let span_guard = trace_cmd!(command);
+        let span_guard = crate::utils::tracing::trace_cmd(command);
 
         let start_time = Instant::now();
         let fingerprint = command.fingerprint();
diff --git a/src/bootstrap/src/utils/step_graph.rs b/src/bootstrap/src/utils/step_graph.rs
index c45825a42223a..cffe0dbb3e3a5 100644
--- a/src/bootstrap/src/utils/step_graph.rs
+++ b/src/bootstrap/src/utils/step_graph.rs
@@ -1,8 +1,10 @@
 use std::collections::{HashMap, HashSet};
 use std::fmt::Debug;
 use std::io::BufWriter;
+use std::path::Path;
 
-use crate::core::builder::{AnyDebug, Step};
+use crate::core::builder::{AnyDebug, Step, pretty_step_name};
+use crate::t;
 
 /// Records the executed steps and their dependencies in a directed graph,
 /// which can then be rendered into a DOT file for visualization.
@@ -41,13 +43,7 @@ impl StepGraph {
                 metadata.get_target()
             )
         } else {
-            let type_name = std::any::type_name::<S>();
-            type_name
-                .strip_prefix("bootstrap::core::")
-                .unwrap_or(type_name)
-                .strip_prefix("build_steps::")
-                .unwrap_or(type_name)
-                .to_string()
+            pretty_step_name::<S>()
         };
 
         let node = Node { label, tooltip: node_key.clone() };
@@ -80,10 +76,10 @@ impl StepGraph {
         }
     }
 
-    pub fn store_to_dot_files(self) {
+    pub fn store_to_dot_files(self, directory: &Path) {
         for (key, graph) in self.graphs.into_iter() {
-            let filename = format!("bootstrap-steps{key}.dot");
-            graph.render(&filename).unwrap();
+            let filename = directory.join(format!("step-graph{key}.dot"));
+            t!(graph.render(&filename));
         }
     }
 }
@@ -147,7 +143,7 @@ impl DotGraph {
         self.key_to_index.get(key).copied()
     }
 
-    fn render(&self, path: &str) -> std::io::Result<()> {
+    fn render(&self, path: &Path) -> std::io::Result<()> {
         use std::io::Write;
 
         let mut file = BufWriter::new(std::fs::File::create(path)?);
diff --git a/src/bootstrap/src/utils/tracing.rs b/src/bootstrap/src/utils/tracing.rs
index 109407bc5f235..428ba013c985f 100644
--- a/src/bootstrap/src/utils/tracing.rs
+++ b/src/bootstrap/src/utils/tracing.rs
@@ -48,17 +48,369 @@ macro_rules! error {
     }
 }
 
-#[macro_export]
-macro_rules! trace_cmd {
-    ($cmd:expr) => {
+#[cfg(feature = "tracing")]
+const COMMAND_SPAN_TARGET: &str = "COMMAND";
+
+#[cfg(feature = "tracing")]
+pub fn trace_cmd(command: &crate::BootstrapCommand) -> tracing::span::EnteredSpan {
+    let fingerprint = command.fingerprint();
+    let location = command.get_created_location();
+    let location = format!("{}:{}", location.file(), location.line());
+
+    tracing::span!(
+        target: COMMAND_SPAN_TARGET,
+        tracing::Level::TRACE,
+        "cmd",
+        cmd_name = fingerprint.program_name().to_string(),
+        cmd = fingerprint.format_short_cmd(),
+        full_cmd = ?command,
+        location
+    )
+    .entered()
+}
+
+// # Note on `tracing` usage in bootstrap
+//
+// Due to the conditional compilation via the `tracing` cargo feature, this means that `tracing`
+// usages in bootstrap need to be also gated behind the `tracing` feature:
+//
+// - `tracing` macros with log levels (`trace!`, `debug!`, `warn!`, `info`, `error`) should not be
+//   used *directly*. You should use the wrapped `tracing` macros which gate the actual invocations
+//   behind `feature = "tracing"`.
+// - `tracing`'s `#[instrument(..)]` macro will need to be gated like `#![cfg_attr(feature =
+//   "tracing", instrument(..))]`.
+#[cfg(feature = "tracing")]
+mod inner {
+    use std::fmt::Debug;
+    use std::fs::File;
+    use std::io::Write;
+    use std::sync::atomic::Ordering;
+
+    use chrono::{DateTime, Utc};
+    use tracing::field::{Field, Visit};
+    use tracing::{Event, Id, Level, Subscriber};
+    use tracing_subscriber::layer::{Context, SubscriberExt};
+    use tracing_subscriber::registry::{LookupSpan, SpanRef};
+    use tracing_subscriber::{EnvFilter, Layer};
+
+    use crate::STEP_SPAN_TARGET;
+    use crate::utils::tracing::COMMAND_SPAN_TARGET;
+
+    pub fn setup_tracing(env_name: &str) -> TracingGuard {
+        let filter = EnvFilter::from_env(env_name);
+
+        let registry = tracing_subscriber::registry().with(filter).with(TracingPrinter::default());
+
+        // When we're creating this layer, we do not yet know the location of the tracing output
+        // directory, because it is stored in the output directory determined after Config is parsed,
+        // but we already want to make tracing calls during (and before) config parsing.
+        // So we store the output into a temporary file, and then move it to the tracing directory
+        // before bootstrap ends.
+        let tempdir = tempfile::TempDir::new().expect("Cannot create temporary directory");
+        let chrome_tracing_path = tempdir.path().join("bootstrap-trace.json");
+        let file = std::io::BufWriter::new(File::create(&chrome_tracing_path).unwrap());
+
+        let chrome_layer = tracing_chrome::ChromeLayerBuilder::new()
+            .writer(file)
+            .include_args(true)
+            .name_fn(Box::new(|event_or_span| match event_or_span {
+                tracing_chrome::EventOrSpan::Event(e) => e.metadata().name().to_string(),
+                tracing_chrome::EventOrSpan::Span(s) => {
+                    if s.metadata().target() == STEP_SPAN_TARGET
+                        && let Some(extension) = s.extensions().get::<StepNameExtension>()
+                    {
+                        extension.0.clone()
+                    } else if s.metadata().target() == COMMAND_SPAN_TARGET
+                        && let Some(extension) = s.extensions().get::<CommandNameExtension>()
+                    {
+                        extension.0.clone()
+                    } else {
+                        s.metadata().name().to_string()
+                    }
+                }
+            }));
+        let (chrome_layer, guard) = chrome_layer.build();
+
+        tracing::subscriber::set_global_default(registry.with(chrome_layer)).unwrap();
+        TracingGuard { guard, _tempdir: tempdir, chrome_tracing_path }
+    }
+
+    pub struct TracingGuard {
+        guard: tracing_chrome::FlushGuard,
+        _tempdir: tempfile::TempDir,
+        chrome_tracing_path: std::path::PathBuf,
+    }
+
+    impl TracingGuard {
+        pub fn copy_to_dir(self, dir: &std::path::Path) {
+            drop(self.guard);
+            std::fs::rename(&self.chrome_tracing_path, dir.join("chrome-trace.json")).unwrap();
+        }
+    }
+
+    /// Visitor that extracts both known and unknown field values from events and spans.
+    #[derive(Default)]
+    struct FieldValues {
+        /// Main event message
+        message: Option<String>,
+        /// Name of a recorded psna
+        step_name: Option<String>,
+        /// Short name of an executed command
+        cmd_name: Option<String>,
+        /// The rest of arbitrary event/span fields
+        fields: Vec<(&'static str, String)>,
+    }
+
+    impl Visit for FieldValues {
+        /// Record fields if possible using `record_str`, to avoid rendering simple strings with
+        /// their `Debug` representation, which adds extra quotes.
+        fn record_str(&mut self, field: &Field, value: &str) {
+            match field.name() {
+                "step_name" => {
+                    self.step_name = Some(value.to_string());
+                }
+                "cmd_name" => {
+                    self.cmd_name = Some(value.to_string());
+                }
+                name => {
+                    self.fields.push((name, value.to_string()));
+                }
+            }
+        }
+
+        fn record_debug(&mut self, field: &Field, value: &dyn Debug) {
+            let formatted = format!("{value:?}");
+            match field.name() {
+                "message" => {
+                    self.message = Some(formatted);
+                }
+                name => {
+                    self.fields.push((name, formatted));
+                }
+            }
+        }
+    }
+
+    #[derive(Copy, Clone)]
+    enum SpanAction {
+        Enter,
+    }
+
+    /// Holds the name of a step span, stored in `tracing_subscriber`'s extensions.
+    struct StepNameExtension(String);
+
+    /// Holds the name of a command span, stored in `tracing_subscriber`'s extensions.
+    struct CommandNameExtension(String);
+
+    #[derive(Default)]
+    struct TracingPrinter {
+        indent: std::sync::atomic::AtomicU32,
+        span_values: std::sync::Mutex<std::collections::HashMap<tracing::Id, FieldValues>>,
+    }
+
+    impl TracingPrinter {
+        fn format_header<W: Write>(
+            &self,
+            writer: &mut W,
+            time: DateTime<Utc>,
+            level: &Level,
+        ) -> std::io::Result<()> {
+            // Use a fixed-width timestamp without date, that shouldn't be very important
+            let timestamp = time.format("%H:%M:%S.%3f");
+            write!(writer, "{timestamp} ")?;
+            // Make sure that levels are aligned to the same number of characters, in order not to
+            // break the layout
+            write!(writer, "{level:>5} ")?;
+            write!(writer, "{}", " ".repeat(self.indent.load(Ordering::Relaxed) as usize))
+        }
+
+        fn write_event<W: Write>(&self, writer: &mut W, event: &Event<'_>) -> std::io::Result<()> {
+            let now = Utc::now();
+
+            self.format_header(writer, now, event.metadata().level())?;
+
+            let mut field_values = FieldValues::default();
+            event.record(&mut field_values);
+
+            if let Some(msg) = &field_values.message {
+                write!(writer, "{msg}")?;
+            }
+
+            if !field_values.fields.is_empty() {
+                if field_values.message.is_some() {
+                    write!(writer, " ")?;
+                }
+                write!(writer, "[")?;
+                for (index, (name, value)) in field_values.fields.iter().enumerate() {
+                    write!(writer, "{name} = {value}")?;
+                    if index < field_values.fields.len() - 1 {
+                        write!(writer, ", ")?;
+                    }
+                }
+                write!(writer, "]")?;
+            }
+            write_location(writer, event.metadata())?;
+            writeln!(writer)?;
+            Ok(())
+        }
+
+        fn write_span<W: Write, S>(
+            &self,
+            writer: &mut W,
+            span: SpanRef<'_, S>,
+            field_values: Option<&FieldValues>,
+            action: SpanAction,
+        ) -> std::io::Result<()>
+        where
+            S: for<'lookup> LookupSpan<'lookup>,
         {
-            ::tracing::span!(
-                target: "COMMAND",
-                ::tracing::Level::TRACE,
-                "executing command",
-                cmd = $cmd.fingerprint().format_short_cmd(),
-                full_cmd = ?$cmd
-            ).entered()
+            let now = Utc::now();
+
+            self.format_header(writer, now, span.metadata().level())?;
+            match action {
+                SpanAction::Enter => {
+                    write!(writer, "> ")?;
+                }
+            }
+
+            fn write_fields<'a, I: IntoIterator<Item = &'a (&'a str, String)>, W: Write>(
+                writer: &mut W,
+                iter: I,
+            ) -> std::io::Result<()> {
+                let items = iter.into_iter().collect::<Vec<_>>();
+                if !items.is_empty() {
+                    write!(writer, " [")?;
+                    for (index, (name, value)) in items.iter().enumerate() {
+                        write!(writer, "{name} = {value}")?;
+                        if index < items.len() - 1 {
+                            write!(writer, ", ")?;
+                        }
+                    }
+                    write!(writer, "]")?;
+                }
+                Ok(())
+            }
+
+            // We handle steps specially. We instrument them dynamically in `Builder::ensure`,
+            // and we want to have custom name for each step span. But tracing doesn't allow setting
+            // dynamic span names. So we detect step spans here and override their name.
+            match span.metadata().target() {
+                // Executed step
+                STEP_SPAN_TARGET => {
+                    let name =
+                        field_values.and_then(|v| v.step_name.as_deref()).unwrap_or(span.name());
+                    write!(writer, "{name}")?;
+
+                    // There should be only one more field called `args`
+                    if let Some(values) = field_values {
+                        let field = &values.fields[0];
+                        write!(writer, " {{{}}}", field.1)?;
+                    }
+                    write_location(writer, span.metadata())?;
+                }
+                // Executed command
+                COMMAND_SPAN_TARGET => {
+                    write!(writer, "{}", span.name())?;
+                    if let Some(values) = field_values {
+                        write_fields(
+                            writer,
+                            values.fields.iter().filter(|(name, _)| *name != "location"),
+                        )?;
+                        write!(
+                            writer,
+                            " ({})",
+                            values.fields.iter().find(|(name, _)| *name == "location").unwrap().1
+                        )?;
+                    }
+                }
+                // Other span
+                _ => {
+                    write!(writer, "{}", span.name())?;
+                    if let Some(values) = field_values {
+                        write_fields(writer, values.fields.iter())?;
+                    }
+                    write_location(writer, span.metadata())?;
+                }
+            }
+
+            writeln!(writer)?;
+            Ok(())
         }
-    };
+    }
+
+    fn write_location<W: Write>(
+        writer: &mut W,
+        metadata: &'static tracing::Metadata<'static>,
+    ) -> std::io::Result<()> {
+        use std::path::{Path, PathBuf};
+
+        if let Some(filename) = metadata.file() {
+            // Keep only the module name and file name to make it shorter
+            let filename: PathBuf = Path::new(filename)
+                .components()
+                // Take last two path components
+                .rev()
+                .take(2)
+                .collect::<Vec<_>>()
+                .into_iter()
+                .rev()
+                .collect();
+
+            write!(writer, " ({}", filename.display())?;
+            if let Some(line) = metadata.line() {
+                write!(writer, ":{line}")?;
+            }
+            write!(writer, ")")?;
+        }
+        Ok(())
+    }
+
+    impl<S> Layer<S> for TracingPrinter
+    where
+        S: Subscriber,
+        S: for<'lookup> LookupSpan<'lookup>,
+    {
+        fn on_new_span(&self, attrs: &tracing::span::Attributes<'_>, id: &Id, ctx: Context<'_, S>) {
+            // Record value of span fields
+            // Note that we do not implement changing values of span fields after they are created.
+            // For that we would also need to implement the `on_record` method
+            let mut field_values = FieldValues::default();
+            attrs.record(&mut field_values);
+
+            // We need to propagate the actual name of the span to the Chrome layer below, because
+            // it cannot access field values. We do that through extensions.
+            if attrs.metadata().target() == STEP_SPAN_TARGET
+                && let Some(step_name) = field_values.step_name.clone()
+            {
+                ctx.span(id).unwrap().extensions_mut().insert(StepNameExtension(step_name));
+            } else if attrs.metadata().target() == COMMAND_SPAN_TARGET
+                && let Some(cmd_name) = field_values.cmd_name.clone()
+            {
+                ctx.span(id).unwrap().extensions_mut().insert(CommandNameExtension(cmd_name));
+            }
+            self.span_values.lock().unwrap().insert(id.clone(), field_values);
+        }
+
+        fn on_event(&self, event: &Event<'_>, _ctx: Context<'_, S>) {
+            let mut writer = std::io::stderr().lock();
+            self.write_event(&mut writer, event).unwrap();
+        }
+
+        fn on_enter(&self, id: &Id, ctx: Context<'_, S>) {
+            if let Some(span) = ctx.span(id) {
+                let mut writer = std::io::stderr().lock();
+                let values = self.span_values.lock().unwrap();
+                let values = values.get(id);
+                self.write_span(&mut writer, span, values, SpanAction::Enter).unwrap();
+            }
+            self.indent.fetch_add(1, Ordering::Relaxed);
+        }
+
+        fn on_exit(&self, _id: &Id, _ctx: Context<'_, S>) {
+            self.indent.fetch_sub(1, Ordering::Relaxed);
+        }
+    }
 }
+
+#[cfg(feature = "tracing")]
+pub use inner::setup_tracing;
diff --git a/src/doc/index.md b/src/doc/index.md
index 8ad5b427b552a..892057a8f4db3 100644
--- a/src/doc/index.md
+++ b/src/doc/index.md
@@ -172,9 +172,9 @@ unsafe Rust. It's also sometimes called "the 'nomicon."
 [The Unstable Book](unstable-book/index.html) has documentation for unstable
 features.
 
-### The `rustc` Contribution Guide
+### The `rustc` Development Guide
 
-[The `rustc` Guide](https://rustc-dev-guide.rust-lang.org/)
+[The `rustc-dev-guide`](https://rustc-dev-guide.rust-lang.org/)
 documents how the compiler works and how to contribute to it. This is useful if
 you want to build or modify the Rust compiler from source (e.g. to target
 something non-standard).
diff --git a/src/doc/rustc-dev-guide/src/building/bootstrapping/debugging-bootstrap.md b/src/doc/rustc-dev-guide/src/building/bootstrapping/debugging-bootstrap.md
index 9c5ebbd36c465..fb90c0fdb4353 100644
--- a/src/doc/rustc-dev-guide/src/building/bootstrapping/debugging-bootstrap.md
+++ b/src/doc/rustc-dev-guide/src/building/bootstrapping/debugging-bootstrap.md
@@ -1,120 +1,100 @@
 # Debugging bootstrap
 
-There are two main ways to debug bootstrap itself. The first is through println logging, and the second is through the `tracing` feature.
-
-> FIXME: this section should be expanded
+There are two main ways of debugging (and profiling bootstrap). The first is through println logging, and the second is through the `tracing` feature.
 
 ## `println` logging
 
 Bootstrap has extensive unstructured logging. Most of it is gated behind the `--verbose` flag (pass `-vv` for even more detail).
 
-If you want to know which `Step` ran a command, you could invoke bootstrap like so:
+If you want to see verbose output of executed Cargo commands and other kinds of detailed logs, pass `-v` or `-vv` when invoking bootstrap. Note that the logs are unstructured and may be overwhelming.
 
 ```
 $ ./x dist rustc --dry-run -vv
 learning about cargo
 running: RUSTC_BOOTSTRAP="1" "/home/jyn/src/rust2/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "metadata" "--format-version" "1" "--no-deps" "--manifest-path" "/home/jyn/src/rust2/Cargo.toml" (failure_mode=Exit) (created at src/bootstrap/src/core/metadata.rs:81:25, executed at src/bootstrap/src/core/metadata.rs:92:50)
 running: RUSTC_BOOTSTRAP="1" "/home/jyn/src/rust2/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "metadata" "--format-version" "1" "--no-deps" "--manifest-path" "/home/jyn/src/rust2/library/Cargo.toml" (failure_mode=Exit) (created at src/bootstrap/src/core/metadata.rs:81:25, executed at src/bootstrap/src/core/metadata.rs:92:50)
-> Assemble { target_compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu } }
-  > Libdir { compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu }, target: x86_64-unknown-linux-gnu }
-    > Sysroot { compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu }, force_recompile: false }
-Removing sysroot /home/jyn/src/rust2/build/tmp-dry-run/x86_64-unknown-linux-gnu/stage1 to avoid caching bugs
-    < Sysroot { compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu }, force_recompile: false }
-  < Libdir { compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu }, target: x86_64-unknown-linux-gnu }
-...
-```
-
-This will go through all the recursive dependency calculations, where `Step`s internally call `builder.ensure()`, without actually running cargo or the compiler.
-
-In some cases, even this may not be enough logging (if so, please add more!). In that case, you can omit `--dry-run`, which will show the normal output inline with the debug logging:
-
-```
-      c Sysroot { compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu }, force_recompile: false }
-using sysroot /home/jyn/src/rust2/build/x86_64-unknown-linux-gnu/stage0-sysroot
-Building stage0 library artifacts (x86_64-unknown-linux-gnu)
-running: cd "/home/jyn/src/rust2" && env ... RUSTC_VERBOSE="2" RUSTC_WRAPPER="/home/jyn/src/rust2/build/bootstrap/debug/rustc" "/home/jyn/src/rust2/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "build" "--target" "x86_64-unknown-linux-gnu" "-Zbinary-dep-depinfo" "-Zroot-dir=/home/jyn/src/rust2" "-v" "-v" "--manifest-path" "/home/jyn/src/rust2/library/sysroot/Cargo.toml" "--message-format" "json-render-diagnostics"
-   0.293440230s  INFO prepare_target{force=false package_id=sysroot v0.0.0 (/home/jyn/src/rust2/library/sysroot) target="sysroot"}: cargo::core::compiler::fingerprint: fingerprint error for sysroot v0.0.0 (/home/jyn/src/rust2/library/sysroot)/Build/TargetInner { name_inferred: true, ..: lib_target("sysroot", ["lib"], "/home/jyn/src/rust2/library/sysroot/src/lib.rs", Edition2021) }
 ...
 ```
 
-In most cases this should not be necessary.
+## `tracing` in bootstrap
 
-TODO: we should convert all this to structured logging so it's easier to control precisely.
+Bootstrap has a conditional `tracing` feature, which provides the following features:
+- It enables structured logging using [`tracing`][tracing] events and spans.
+- It generates a [Chrome trace file] that can be used to visualize the hierarchy and durations of executed steps and commands.
+  - You can open the generated `chrome-trace.json` file using Chrome, on the `chrome://tracing` tab, or e.g. using [Perfetto].
+- It generates [GraphViz] graphs that visualize the dependencies between executed steps.
+  - You can open the generated `step-graph-*.dot` file using e.g. [xdot] to visualize the step graph, or use e.g. `dot -Tsvg` to convert the GraphViz file to an SVG file.
+- It generates a command execution summary, which shows which commands were executed, how many of their executions were cached, and what commands were the slowest to run.
+  - The generated `command-stats.txt` file is in a simple human-readable format.
 
-## `tracing` in bootstrap
+The structured logs will be written to standard error output (`stderr`), while the other outputs will be stored in files in the `<build-dir>/bootstrap-trace/<pid>` directory. For convenience, bootstrap will also create a symlink to the latest generated trace output directory at `<build-dir>/bootstrap-trace/latest`.
 
-Bootstrap has conditional [`tracing`][tracing] setup to provide structured logging.
+> Note that if you execute bootstrap with `--dry-run`, the tracing output directory might change. Bootstrap will always print a path where the tracing output files were stored at the end of its execution.
 
 [tracing]: https://docs.rs/tracing/0.1.41/tracing/index.html
+[Chrome trace file]: https://www.chromium.org/developers/how-tos/trace-event-profiling-tool/
+[Perfetto]: https://ui.perfetto.dev/
+[GraphViz]: https://graphviz.org/doc/info/lang.html
+[xdot]: https://github.com/jrfonseca/xdot.py
 
 ### Enabling `tracing` output
 
-Bootstrap will conditionally build `tracing` support and enable `tracing` output if the `BOOTSTRAP_TRACING` env var is set.
-
-#### Basic usage
-
-Example basic usage[^just-trace]:
+To enable the conditional `tracing` feature, run bootstrap with the `BOOTSTRAP_TRACING` environment variable.
 
-[^just-trace]: It is not recommended to use *just* `BOOTSTRAP_TRACING=TRACE` because that will dump *everything* at `TRACE` level, including logs intentionally gated behind custom targets as they are too verbose even for `TRACE` level by default.
+[tracing_subscriber filter]: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html
 
 ```bash
-$ BOOTSTRAP_TRACING=bootstrap=TRACE ./x build library --stage 1
+$ BOOTSTRAP_TRACING=trace ./x build library --stage 1
 ```
 
 Example output[^unstable]:
 
 ```
-$ BOOTSTRAP_TRACING=bootstrap=TRACE ./x check src/bootstrap/
+$ BOOTSTRAP_TRACING=trace ./x build library --stage 1 --dry-run
 Building bootstrap
-   Compiling bootstrap v0.0.0 (/home/joe/repos/rust/src/bootstrap)
-    Finished `dev` profile [unoptimized] target(s) in 2.74s
- DEBUG bootstrap parsing flags
- bootstrap::core::config::flags::Flags::parse args=["check", "src/bootstrap/"]
- DEBUG bootstrap parsing config based on flags
- DEBUG bootstrap creating new build based on config
- bootstrap::Build::build
-  TRACE bootstrap setting up job management
-  TRACE bootstrap downloading rustfmt early
-   bootstrap::handling hardcoded subcommands (Format, Suggest, Perf)
-    DEBUG bootstrap not a hardcoded subcommand; returning to normal handling, cmd=Check { all_targets: false }
-  DEBUG bootstrap handling subcommand normally
-   bootstrap::executing real run
-     bootstrap::(1) executing dry-run sanity-check
-     bootstrap::(2) executing actual run
-Checking stage0 library artifacts (x86_64-unknown-linux-gnu)
-    Finished `release` profile [optimized + debuginfo] target(s) in 0.04s
-Checking stage0 compiler artifacts {rustc-main, rustc_abi, rustc_arena, rustc_ast, rustc_ast_ir, rustc_ast_lowering, rustc_ast_passes, rustc_ast_pretty, rustc_attr_data_structures, rustc_attr_parsing, rustc_baked_icu_data, rustc_borrowck, rustc_builtin_macros, rustc_codegen_llvm, rustc_codegen_ssa, rustc_const_eval, rustc_data_structures, rustc_driver, rustc_driver_impl, rustc_error_codes, rustc_error_messages, rustc_errors, rustc_expand, rustc_feature, rustc_fluent_macro, rustc_fs_util, rustc_graphviz, rustc_hir, rustc_hir_analysis, rustc_hir_pretty, rustc_hir_typeck, rustc_incremental, rustc_index, rustc_index_macros, rustc_infer, rustc_interface, rustc_lexer, rustc_lint, rustc_lint_defs, rustc_llvm, rustc_log, rustc_macros, rustc_metadata, rustc_middle, rustc_mir_build, rustc_mir_dataflow, rustc_mir_transform, rustc_monomorphize, rustc_next_trait_solver, rustc_parse, rustc_parse_format, rustc_passes, rustc_pattern_analysis, rustc_privacy, rustc_query_impl, rustc_query_system, rustc_resolve, rustc_sanitizers, rustc_serialize, rustc_session, rustc_smir, rustc_span, rustc_symbol_mangling, rustc_target, rustc_trait_selection, rustc_traits, rustc_transmute, rustc_ty_utils, rustc_type_ir, rustc_type_ir_macros, stable_mir} (x86_64-unknown-linux-gnu)
-    Finished `release` profile [optimized + debuginfo] target(s) in 0.23s
-Checking stage0 bootstrap artifacts (x86_64-unknown-linux-gnu)
-    Checking bootstrap v0.0.0 (/home/joe/repos/rust/src/bootstrap)
-    Finished `release` profile [optimized + debuginfo] target(s) in 0.64s
-  DEBUG bootstrap checking for postponed test failures from `test  --no-fail-fast`
-Build completed successfully in 0:00:08
+    Finished `dev` profile [unoptimized] target(s) in 0.05s
+15:56:52.477  INFO > tool::LibcxxVersionTool {target: x86_64-unknown-linux-gnu} (builder/mod.rs:1715)
+15:56:52.575  INFO > compile::Assemble {target_compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }} (builder/mod.rs:1715)
+15:56:52.575  INFO > tool::Compiletest {compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu} (builder/mod.rs:1715)
+15:56:52.576  INFO  > tool::ToolBuild {build_compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu, tool: "compiletest", path: "src/tools/compiletest", mode: ToolBootstrap, source_type: InTree, extra_features: [], allow_features: "internal_output_capture", cargo_args: [], artifact_kind: Binary} (builder/mod.rs:1715)
+15:56:52.576  INFO   > builder::Libdir {compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu} (builder/mod.rs:1715)
+15:56:52.576  INFO    > compile::Sysroot {compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, force_recompile: false} (builder/mod.rs:1715)
+15:56:52.578  INFO > compile::Assemble {target_compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }} (builder/mod.rs:1715)
+15:56:52.578  INFO > tool::Compiletest {compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu} (builder/mod.rs:1715)
+15:56:52.578  INFO  > tool::ToolBuild {build_compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu, tool: "compiletest", path: "src/tools/compiletest", mode: ToolBootstrap, source_type: InTree, extra_features: [], allow_features: "internal_output_capture", cargo_args: [], artifact_kind: Binary} (builder/mod.rs:1715)
+15:56:52.578  INFO   > builder::Libdir {compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu} (builder/mod.rs:1715)
+15:56:52.578  INFO    > compile::Sysroot {compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, force_recompile: false} (builder/mod.rs:1715)
+    Finished `release` profile [optimized] target(s) in 0.11s
+Tracing/profiling output has been written to <src-root>/build/bootstrap-trace/latest
+Build completed successfully in 0:00:00
 ```
 
+[^unstable]: This output is always subject to further changes.
+
 #### Controlling tracing output
 
-The env var `BOOTSTRAP_TRACING` accepts a [`tracing` env-filter][tracing-env-filter].
+The environment variable `BOOTSTRAP_TRACING` accepts a [`tracing_subscriber` filter][tracing-env-filter]. If you set `BOOTSTRAP_TRACING=trace`, you will enable all logs, but that can be overwhelming. You can thus use the filter to reduce the amount of data logged.
 
 There are two orthogonal ways to control which kind of tracing logs you want:
 
-1. You can specify the log **level**, e.g. `DEBUG` or `TRACE`.
-2. You can also control the log **target**, e.g. `bootstrap` or `bootstrap::core::config` vs custom targets like `CONFIG_HANDLING`.
-    - Custom targets are used to limit what is output when `BOOTSTRAP_TRACING=bootstrap=TRACE` is used, as they can be too verbose even for `TRACE` level by default. Currently used custom targets:
-        - `CONFIG_HANDLING`
-
-The `TRACE` filter will enable *all* `trace` level or less verbose level tracing output.
+1. You can specify the log **level**, e.g. `debug` or `trace`.
+   - If you select a level, all events/spans with an equal or higher priority level will be shown.
+2. You can also control the log **target**, e.g. `bootstrap` or `bootstrap::core::config` or a custom target like `CONFIG_HANDLING` or `STEP`.
+    - Custom targets are used to limit what kinds of spans you are interested in, as the `BOOTSTRAP_TRACING=trace` output can be quite verbose. Currently, you can use the following custom targets:
+        - `CONFIG_HANDLING`: show spans related to config handling
+        - `STEP`: show all executed steps. Note that executed commands have `info` event level.
+        - `COMMAND`: show all executed commands. Note that executed commands have `trace` event level.
 
 You can of course combine them (custom target logs are typically gated behind `TRACE` log level additionally):
 
 ```bash
-$ BOOTSTRAP_TRACING=CONFIG_HANDLING=TRACE ./x build library --stage 1
+$ BOOTSTRAP_TRACING=CONFIG_HANDLING=trace,STEP=info,COMMAND=trace ./x build library --stage 1
 ```
 
-[^unstable]: This output is always subject to further changes.
-
 [tracing-env-filter]: https://docs.rs/tracing-subscriber/0.3.19/tracing_subscriber/filter/struct.EnvFilter.html
 
+Note that the level that you specify using `BOOTSTRAP_TRACING` also has an effect on the spans that will be recorded in the Chrome trace file.
+
 ##### FIXME(#96176): specific tracing for `compiler()` vs `compiler_for()`
 
 The additional targets `COMPILER` and `COMPILER_FOR` are used to help trace what
@@ -123,12 +103,6 @@ if [#96176][cleanup-compiler-for] is resolved.
 
 [cleanup-compiler-for]: https://github.com/rust-lang/rust/issues/96176
 
-### Rendering step graph
-
-When you run bootstrap with the `BOOTSTRAP_TRACING` environment variable configured, bootstrap will automatically output a DOT file that shows all executed steps and their dependencies. The files will have a prefix `bootstrap-steps`. You can use e.g. `xdot` to visualize the file or e.g. `dot -Tsvg` to convert the DOT file to a SVG file.
-
-A separate DOT file will be outputted for dry-run and non-dry-run execution.
-
 ### Using `tracing` in bootstrap
 
 Both `tracing::*` macros and the `tracing::instrument` proc-macro attribute need to be gated behind `tracing` feature. Examples:
@@ -149,15 +123,6 @@ impl Step for Foo {
         todo!()
     }
 
-    #[cfg_attr(
-        feature = "tracing",
-        instrument(
-            level = "trace",
-            name = "Foo::run",
-            skip_all,
-            fields(compiler = ?builder.compiler),
-        ),
-    )]
     fn run(self, builder: &Builder<'_>) -> Self::Output {
         trace!(?run, "entered Foo::run");
 
@@ -172,21 +137,6 @@ For `#[instrument]`, it's recommended to:
 - Explicitly pick an instrumentation name via `name = ".."` to distinguish between e.g. `run` of different steps.
 - Take care to not cause diverging behavior via tracing, e.g. building extra things only when tracing infra is enabled.
 
-### Profiling bootstrap
-
-You can set the `BOOTSTRAP_PROFILE=1` environment variable to enable command execution profiling during bootstrap. This generates:
-
-* A Chrome trace file (for visualization in `chrome://tracing` or [Perfetto](https://ui.perfetto.dev)) if tracing is enabled via `BOOTSTRAP_TRACING=COMMAND=trace`
-* A plain-text summary file, `bootstrap-profile-{pid}.txt`, listing all commands sorted by execution time (slowest first), along with cache hits and working directories
-
-Note: the `.txt` report is always generated when `BOOTSTRAP_PROFILE=1` is set — tracing is not required.
-
-Example usage:
-
-```bash
-$ BOOTSTRAP_PROFILE=1 BOOTSTRAP_TRACING=COMMAND=trace ./x build library
-```
-
 ### rust-analyzer integration?
 
 Unfortunately, because bootstrap is a `rust-analyzer.linkedProjects`, you can't ask r-a to check/build bootstrap itself with `tracing` feature enabled to get relevant completions, due to lack of support as described in <https://github.com/rust-lang/rust-analyzer/issues/8521>.
diff --git a/src/etc/completions/x.fish b/src/etc/completions/x.fish
index a5e5bb8f09e81..0b9af33421461 100644
--- a/src/etc/completions/x.fish
+++ b/src/etc/completions/x.fish
@@ -97,6 +97,7 @@ complete -c x -n "__fish_x_using_subcommand build" -l llvm-profile-use -d 'use P
 complete -c x -n "__fish_x_using_subcommand build" -l reproducible-artifact -d 'Additional reproducible artifacts that should be added to the reproducible artifacts archive' -r
 complete -c x -n "__fish_x_using_subcommand build" -l set -d 'override options in bootstrap.toml' -r -f
 complete -c x -n "__fish_x_using_subcommand build" -l ci -d 'Make bootstrap to behave as it\'s running on the CI environment or not' -r -f -a "{true\t'',false\t''}"
+complete -c x -n "__fish_x_using_subcommand build" -l timings -d 'Pass `--timings` to Cargo to get crate build timings'
 complete -c x -n "__fish_x_using_subcommand build" -s v -l verbose -d 'use verbose output (-vv for very verbose)'
 complete -c x -n "__fish_x_using_subcommand build" -s i -l incremental -d 'use incremental compilation'
 complete -c x -n "__fish_x_using_subcommand build" -l include-default-paths -d 'include default paths in addition to the provided ones'
@@ -133,6 +134,7 @@ complete -c x -n "__fish_x_using_subcommand check" -l reproducible-artifact -d '
 complete -c x -n "__fish_x_using_subcommand check" -l set -d 'override options in bootstrap.toml' -r -f
 complete -c x -n "__fish_x_using_subcommand check" -l ci -d 'Make bootstrap to behave as it\'s running on the CI environment or not' -r -f -a "{true\t'',false\t''}"
 complete -c x -n "__fish_x_using_subcommand check" -l all-targets -d 'Check all targets'
+complete -c x -n "__fish_x_using_subcommand check" -l timings -d 'Pass `--timings` to Cargo to get crate build timings'
 complete -c x -n "__fish_x_using_subcommand check" -s v -l verbose -d 'use verbose output (-vv for very verbose)'
 complete -c x -n "__fish_x_using_subcommand check" -s i -l incremental -d 'use incremental compilation'
 complete -c x -n "__fish_x_using_subcommand check" -l include-default-paths -d 'include default paths in addition to the provided ones'
diff --git a/src/etc/completions/x.ps1 b/src/etc/completions/x.ps1
index 4fee3bc0a8692..95cee4b633625 100644
--- a/src/etc/completions/x.ps1
+++ b/src/etc/completions/x.ps1
@@ -102,6 +102,7 @@ Register-ArgumentCompleter -Native -CommandName 'x' -ScriptBlock {
             [CompletionResult]::new('--reproducible-artifact', '--reproducible-artifact', [CompletionResultType]::ParameterName, 'Additional reproducible artifacts that should be added to the reproducible artifacts archive')
             [CompletionResult]::new('--set', '--set', [CompletionResultType]::ParameterName, 'override options in bootstrap.toml')
             [CompletionResult]::new('--ci', '--ci', [CompletionResultType]::ParameterName, 'Make bootstrap to behave as it''s running on the CI environment or not')
+            [CompletionResult]::new('--timings', '--timings', [CompletionResultType]::ParameterName, 'Pass `--timings` to Cargo to get crate build timings')
             [CompletionResult]::new('-v', '-v', [CompletionResultType]::ParameterName, 'use verbose output (-vv for very verbose)')
             [CompletionResult]::new('--verbose', '--verbose', [CompletionResultType]::ParameterName, 'use verbose output (-vv for very verbose)')
             [CompletionResult]::new('-i', '-i', [CompletionResultType]::ParameterName, 'use incremental compilation')
@@ -145,6 +146,7 @@ Register-ArgumentCompleter -Native -CommandName 'x' -ScriptBlock {
             [CompletionResult]::new('--set', '--set', [CompletionResultType]::ParameterName, 'override options in bootstrap.toml')
             [CompletionResult]::new('--ci', '--ci', [CompletionResultType]::ParameterName, 'Make bootstrap to behave as it''s running on the CI environment or not')
             [CompletionResult]::new('--all-targets', '--all-targets', [CompletionResultType]::ParameterName, 'Check all targets')
+            [CompletionResult]::new('--timings', '--timings', [CompletionResultType]::ParameterName, 'Pass `--timings` to Cargo to get crate build timings')
             [CompletionResult]::new('-v', '-v', [CompletionResultType]::ParameterName, 'use verbose output (-vv for very verbose)')
             [CompletionResult]::new('--verbose', '--verbose', [CompletionResultType]::ParameterName, 'use verbose output (-vv for very verbose)')
             [CompletionResult]::new('-i', '-i', [CompletionResultType]::ParameterName, 'use incremental compilation')
diff --git a/src/etc/completions/x.py.fish b/src/etc/completions/x.py.fish
index e2e6ae05ee03d..6fba6a4562368 100644
--- a/src/etc/completions/x.py.fish
+++ b/src/etc/completions/x.py.fish
@@ -97,6 +97,7 @@ complete -c x.py -n "__fish_x.py_using_subcommand build" -l llvm-profile-use -d
 complete -c x.py -n "__fish_x.py_using_subcommand build" -l reproducible-artifact -d 'Additional reproducible artifacts that should be added to the reproducible artifacts archive' -r
 complete -c x.py -n "__fish_x.py_using_subcommand build" -l set -d 'override options in bootstrap.toml' -r -f
 complete -c x.py -n "__fish_x.py_using_subcommand build" -l ci -d 'Make bootstrap to behave as it\'s running on the CI environment or not' -r -f -a "{true\t'',false\t''}"
+complete -c x.py -n "__fish_x.py_using_subcommand build" -l timings -d 'Pass `--timings` to Cargo to get crate build timings'
 complete -c x.py -n "__fish_x.py_using_subcommand build" -s v -l verbose -d 'use verbose output (-vv for very verbose)'
 complete -c x.py -n "__fish_x.py_using_subcommand build" -s i -l incremental -d 'use incremental compilation'
 complete -c x.py -n "__fish_x.py_using_subcommand build" -l include-default-paths -d 'include default paths in addition to the provided ones'
@@ -133,6 +134,7 @@ complete -c x.py -n "__fish_x.py_using_subcommand check" -l reproducible-artifac
 complete -c x.py -n "__fish_x.py_using_subcommand check" -l set -d 'override options in bootstrap.toml' -r -f
 complete -c x.py -n "__fish_x.py_using_subcommand check" -l ci -d 'Make bootstrap to behave as it\'s running on the CI environment or not' -r -f -a "{true\t'',false\t''}"
 complete -c x.py -n "__fish_x.py_using_subcommand check" -l all-targets -d 'Check all targets'
+complete -c x.py -n "__fish_x.py_using_subcommand check" -l timings -d 'Pass `--timings` to Cargo to get crate build timings'
 complete -c x.py -n "__fish_x.py_using_subcommand check" -s v -l verbose -d 'use verbose output (-vv for very verbose)'
 complete -c x.py -n "__fish_x.py_using_subcommand check" -s i -l incremental -d 'use incremental compilation'
 complete -c x.py -n "__fish_x.py_using_subcommand check" -l include-default-paths -d 'include default paths in addition to the provided ones'
diff --git a/src/etc/completions/x.py.ps1 b/src/etc/completions/x.py.ps1
index ea3aacc21c7ac..458879a17a7b9 100644
--- a/src/etc/completions/x.py.ps1
+++ b/src/etc/completions/x.py.ps1
@@ -102,6 +102,7 @@ Register-ArgumentCompleter -Native -CommandName 'x.py' -ScriptBlock {
             [CompletionResult]::new('--reproducible-artifact', '--reproducible-artifact', [CompletionResultType]::ParameterName, 'Additional reproducible artifacts that should be added to the reproducible artifacts archive')
             [CompletionResult]::new('--set', '--set', [CompletionResultType]::ParameterName, 'override options in bootstrap.toml')
             [CompletionResult]::new('--ci', '--ci', [CompletionResultType]::ParameterName, 'Make bootstrap to behave as it''s running on the CI environment or not')
+            [CompletionResult]::new('--timings', '--timings', [CompletionResultType]::ParameterName, 'Pass `--timings` to Cargo to get crate build timings')
             [CompletionResult]::new('-v', '-v', [CompletionResultType]::ParameterName, 'use verbose output (-vv for very verbose)')
             [CompletionResult]::new('--verbose', '--verbose', [CompletionResultType]::ParameterName, 'use verbose output (-vv for very verbose)')
             [CompletionResult]::new('-i', '-i', [CompletionResultType]::ParameterName, 'use incremental compilation')
@@ -145,6 +146,7 @@ Register-ArgumentCompleter -Native -CommandName 'x.py' -ScriptBlock {
             [CompletionResult]::new('--set', '--set', [CompletionResultType]::ParameterName, 'override options in bootstrap.toml')
             [CompletionResult]::new('--ci', '--ci', [CompletionResultType]::ParameterName, 'Make bootstrap to behave as it''s running on the CI environment or not')
             [CompletionResult]::new('--all-targets', '--all-targets', [CompletionResultType]::ParameterName, 'Check all targets')
+            [CompletionResult]::new('--timings', '--timings', [CompletionResultType]::ParameterName, 'Pass `--timings` to Cargo to get crate build timings')
             [CompletionResult]::new('-v', '-v', [CompletionResultType]::ParameterName, 'use verbose output (-vv for very verbose)')
             [CompletionResult]::new('--verbose', '--verbose', [CompletionResultType]::ParameterName, 'use verbose output (-vv for very verbose)')
             [CompletionResult]::new('-i', '-i', [CompletionResultType]::ParameterName, 'use incremental compilation')
diff --git a/src/etc/completions/x.py.sh b/src/etc/completions/x.py.sh
index f31bdb58dc448..e003bf7fd0b43 100644
--- a/src/etc/completions/x.py.sh
+++ b/src/etc/completions/x.py.sh
@@ -458,7 +458,7 @@ _x.py() {
             return 0
             ;;
         x.py__build)
-            opts="-v -i -j -h --verbose --incremental --config --build-dir --build --host --target --exclude --skip --include-default-paths --rustc-error-format --on-fail --dry-run --dump-bootstrap-shims --stage --keep-stage --keep-stage-std --src --jobs --warnings --json-output --compile-time-deps --color --bypass-bootstrap-lock --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --enable-bolt-settings --skip-stage0-validation --reproducible-artifact --set --ci --skip-std-check-if-no-download-rustc --help [PATHS]... [ARGS]..."
+            opts="-v -i -j -h --timings --verbose --incremental --config --build-dir --build --host --target --exclude --skip --include-default-paths --rustc-error-format --on-fail --dry-run --dump-bootstrap-shims --stage --keep-stage --keep-stage-std --src --jobs --warnings --json-output --compile-time-deps --color --bypass-bootstrap-lock --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --enable-bolt-settings --skip-stage0-validation --reproducible-artifact --set --ci --skip-std-check-if-no-download-rustc --help [PATHS]... [ARGS]..."
             if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                 COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                 return 0
@@ -644,7 +644,7 @@ _x.py() {
             return 0
             ;;
         x.py__check)
-            opts="-v -i -j -h --all-targets --verbose --incremental --config --build-dir --build --host --target --exclude --skip --include-default-paths --rustc-error-format --on-fail --dry-run --dump-bootstrap-shims --stage --keep-stage --keep-stage-std --src --jobs --warnings --json-output --compile-time-deps --color --bypass-bootstrap-lock --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --enable-bolt-settings --skip-stage0-validation --reproducible-artifact --set --ci --skip-std-check-if-no-download-rustc --help [PATHS]... [ARGS]..."
+            opts="-v -i -j -h --all-targets --timings --verbose --incremental --config --build-dir --build --host --target --exclude --skip --include-default-paths --rustc-error-format --on-fail --dry-run --dump-bootstrap-shims --stage --keep-stage --keep-stage-std --src --jobs --warnings --json-output --compile-time-deps --color --bypass-bootstrap-lock --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --enable-bolt-settings --skip-stage0-validation --reproducible-artifact --set --ci --skip-std-check-if-no-download-rustc --help [PATHS]... [ARGS]..."
             if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                 COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                 return 0
diff --git a/src/etc/completions/x.py.zsh b/src/etc/completions/x.py.zsh
index 32e986ad141fa..b82c2d65e8694 100644
--- a/src/etc/completions/x.py.zsh
+++ b/src/etc/completions/x.py.zsh
@@ -90,6 +90,7 @@ _arguments "${_arguments_options[@]}" : \
 '*--reproducible-artifact=[Additional reproducible artifacts that should be added to the reproducible artifacts archive]:REPRODUCIBLE_ARTIFACT:_default' \
 '*--set=[override options in bootstrap.toml]:section.option=value:' \
 '--ci=[Make bootstrap to behave as it'\''s running on the CI environment or not]:bool:(true false)' \
+'--timings[Pass \`--timings\` to Cargo to get crate build timings]' \
 '*-v[use verbose output (-vv for very verbose)]' \
 '*--verbose[use verbose output (-vv for very verbose)]' \
 '-i[use incremental compilation]' \
@@ -135,6 +136,7 @@ _arguments "${_arguments_options[@]}" : \
 '*--set=[override options in bootstrap.toml]:section.option=value:' \
 '--ci=[Make bootstrap to behave as it'\''s running on the CI environment or not]:bool:(true false)' \
 '--all-targets[Check all targets]' \
+'--timings[Pass \`--timings\` to Cargo to get crate build timings]' \
 '*-v[use verbose output (-vv for very verbose)]' \
 '*--verbose[use verbose output (-vv for very verbose)]' \
 '-i[use incremental compilation]' \
diff --git a/src/etc/completions/x.sh b/src/etc/completions/x.sh
index 927d8f7661cd3..c2cb771002017 100644
--- a/src/etc/completions/x.sh
+++ b/src/etc/completions/x.sh
@@ -458,7 +458,7 @@ _x() {
             return 0
             ;;
         x__build)
-            opts="-v -i -j -h --verbose --incremental --config --build-dir --build --host --target --exclude --skip --include-default-paths --rustc-error-format --on-fail --dry-run --dump-bootstrap-shims --stage --keep-stage --keep-stage-std --src --jobs --warnings --json-output --compile-time-deps --color --bypass-bootstrap-lock --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --enable-bolt-settings --skip-stage0-validation --reproducible-artifact --set --ci --skip-std-check-if-no-download-rustc --help [PATHS]... [ARGS]..."
+            opts="-v -i -j -h --timings --verbose --incremental --config --build-dir --build --host --target --exclude --skip --include-default-paths --rustc-error-format --on-fail --dry-run --dump-bootstrap-shims --stage --keep-stage --keep-stage-std --src --jobs --warnings --json-output --compile-time-deps --color --bypass-bootstrap-lock --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --enable-bolt-settings --skip-stage0-validation --reproducible-artifact --set --ci --skip-std-check-if-no-download-rustc --help [PATHS]... [ARGS]..."
             if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                 COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                 return 0
@@ -644,7 +644,7 @@ _x() {
             return 0
             ;;
         x__check)
-            opts="-v -i -j -h --all-targets --verbose --incremental --config --build-dir --build --host --target --exclude --skip --include-default-paths --rustc-error-format --on-fail --dry-run --dump-bootstrap-shims --stage --keep-stage --keep-stage-std --src --jobs --warnings --json-output --compile-time-deps --color --bypass-bootstrap-lock --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --enable-bolt-settings --skip-stage0-validation --reproducible-artifact --set --ci --skip-std-check-if-no-download-rustc --help [PATHS]... [ARGS]..."
+            opts="-v -i -j -h --all-targets --timings --verbose --incremental --config --build-dir --build --host --target --exclude --skip --include-default-paths --rustc-error-format --on-fail --dry-run --dump-bootstrap-shims --stage --keep-stage --keep-stage-std --src --jobs --warnings --json-output --compile-time-deps --color --bypass-bootstrap-lock --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --enable-bolt-settings --skip-stage0-validation --reproducible-artifact --set --ci --skip-std-check-if-no-download-rustc --help [PATHS]... [ARGS]..."
             if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                 COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                 return 0
diff --git a/src/etc/completions/x.zsh b/src/etc/completions/x.zsh
index 65995553276d9..49139e70f7fb2 100644
--- a/src/etc/completions/x.zsh
+++ b/src/etc/completions/x.zsh
@@ -90,6 +90,7 @@ _arguments "${_arguments_options[@]}" : \
 '*--reproducible-artifact=[Additional reproducible artifacts that should be added to the reproducible artifacts archive]:REPRODUCIBLE_ARTIFACT:_default' \
 '*--set=[override options in bootstrap.toml]:section.option=value:' \
 '--ci=[Make bootstrap to behave as it'\''s running on the CI environment or not]:bool:(true false)' \
+'--timings[Pass \`--timings\` to Cargo to get crate build timings]' \
 '*-v[use verbose output (-vv for very verbose)]' \
 '*--verbose[use verbose output (-vv for very verbose)]' \
 '-i[use incremental compilation]' \
@@ -135,6 +136,7 @@ _arguments "${_arguments_options[@]}" : \
 '*--set=[override options in bootstrap.toml]:section.option=value:' \
 '--ci=[Make bootstrap to behave as it'\''s running on the CI environment or not]:bool:(true false)' \
 '--all-targets[Check all targets]' \
+'--timings[Pass \`--timings\` to Cargo to get crate build timings]' \
 '*-v[use verbose output (-vv for very verbose)]' \
 '*--verbose[use verbose output (-vv for very verbose)]' \
 '-i[use incremental compilation]' \
diff --git a/tests/ui/issues/issue-8498.rs b/tests/ui/array-slice-vec/matching-on-vector-slice-option-8498.rs
similarity index 91%
rename from tests/ui/issues/issue-8498.rs
rename to tests/ui/array-slice-vec/matching-on-vector-slice-option-8498.rs
index 92904e2198f68..e243a247ed518 100644
--- a/tests/ui/issues/issue-8498.rs
+++ b/tests/ui/array-slice-vec/matching-on-vector-slice-option-8498.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8498
 //@ run-pass
 
 pub fn main() {
diff --git a/tests/ui/issues/issue-7784.rs b/tests/ui/array-slice-vec/pattern-matching-fixed-length-vectors-7784.rs
similarity index 93%
rename from tests/ui/issues/issue-7784.rs
rename to tests/ui/array-slice-vec/pattern-matching-fixed-length-vectors-7784.rs
index 90b88ae572764..7d987e92b63aa 100644
--- a/tests/ui/issues/issue-7784.rs
+++ b/tests/ui/array-slice-vec/pattern-matching-fixed-length-vectors-7784.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/7784
 //@ run-pass
 
 use std::ops::Add;
diff --git a/tests/ui/issues/issue-78622.rs b/tests/ui/associated-consts/ambiguous-associated-type-error-78622.rs
similarity index 67%
rename from tests/ui/issues/issue-78622.rs
rename to tests/ui/associated-consts/ambiguous-associated-type-error-78622.rs
index c00fd26606367..9763be1ecb219 100644
--- a/tests/ui/issues/issue-78622.rs
+++ b/tests/ui/associated-consts/ambiguous-associated-type-error-78622.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/78622
 #![crate_type = "lib"]
 
 struct S;
diff --git a/tests/ui/issues/issue-78622.stderr b/tests/ui/associated-consts/ambiguous-associated-type-error-78622.stderr
similarity index 87%
rename from tests/ui/issues/issue-78622.stderr
rename to tests/ui/associated-consts/ambiguous-associated-type-error-78622.stderr
index 432913a0fc9c1..4dff1364af777 100644
--- a/tests/ui/issues/issue-78622.stderr
+++ b/tests/ui/associated-consts/ambiguous-associated-type-error-78622.stderr
@@ -1,5 +1,5 @@
 error[E0223]: ambiguous associated type
-  --> $DIR/issue-78622.rs:5:5
+  --> $DIR/ambiguous-associated-type-error-78622.rs:6:5
    |
 LL |     S::A::<f> {}
    |     ^^^^
diff --git a/tests/ui/issues/issue-78957.rs b/tests/ui/attributes/invalid-attributes-on-const-params-78957.rs
similarity index 95%
rename from tests/ui/issues/issue-78957.rs
rename to tests/ui/attributes/invalid-attributes-on-const-params-78957.rs
index 567c59fd560d9..29f8efcc922e8 100644
--- a/tests/ui/issues/issue-78957.rs
+++ b/tests/ui/attributes/invalid-attributes-on-const-params-78957.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/78957
 #![deny(unused_attributes)]
 
 use std::marker::PhantomData;
diff --git a/tests/ui/issues/issue-78957.stderr b/tests/ui/attributes/invalid-attributes-on-const-params-78957.stderr
similarity index 79%
rename from tests/ui/issues/issue-78957.stderr
rename to tests/ui/attributes/invalid-attributes-on-const-params-78957.stderr
index 6de22d6bf79fc..6271384aaf962 100644
--- a/tests/ui/issues/issue-78957.stderr
+++ b/tests/ui/attributes/invalid-attributes-on-const-params-78957.stderr
@@ -1,36 +1,36 @@
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-78957.rs:5:16
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:6:16
    |
 LL | pub struct Foo<#[inline] const N: usize>;
    |                ^^^^^^^^^ -------------- not a function or closure
 
 error: attribute should be applied to a function definition
-  --> $DIR/issue-78957.rs:7:16
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:8:16
    |
 LL | pub struct Bar<#[cold] const N: usize>;
    |                ^^^^^^^ -------------- not a function definition
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 note: the lint level is defined here
-  --> $DIR/issue-78957.rs:1:9
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:2:9
    |
 LL | #![deny(unused_attributes)]
    |         ^^^^^^^^^^^^^^^^^
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-78957.rs:10:23
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:11:23
    |
 LL | pub struct Baz<#[repr(C)] const N: usize>;
    |                       ^   -------------- not a struct, enum, or union
 
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-78957.rs:13:17
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:14:17
    |
 LL | pub struct Foo2<#[inline] 'a>(PhantomData<&'a ()>);
    |                 ^^^^^^^^^ -- not a function or closure
 
 error: attribute should be applied to a function definition
-  --> $DIR/issue-78957.rs:15:17
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:16:17
    |
 LL | pub struct Bar2<#[cold] 'a>(PhantomData<&'a ()>);
    |                 ^^^^^^^ -- not a function definition
@@ -38,19 +38,19 @@ LL | pub struct Bar2<#[cold] 'a>(PhantomData<&'a ()>);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-78957.rs:18:24
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:19:24
    |
 LL | pub struct Baz2<#[repr(C)] 'a>(PhantomData<&'a ()>);
    |                        ^   -- not a struct, enum, or union
 
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-78957.rs:21:17
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:22:17
    |
 LL | pub struct Foo3<#[inline] T>(PhantomData<T>);
    |                 ^^^^^^^^^ - not a function or closure
 
 error: attribute should be applied to a function definition
-  --> $DIR/issue-78957.rs:23:17
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:24:17
    |
 LL | pub struct Bar3<#[cold] T>(PhantomData<T>);
    |                 ^^^^^^^ - not a function definition
@@ -58,7 +58,7 @@ LL | pub struct Bar3<#[cold] T>(PhantomData<T>);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-78957.rs:26:24
+  --> $DIR/invalid-attributes-on-const-params-78957.rs:27:24
    |
 LL | pub struct Baz3<#[repr(C)] T>(PhantomData<T>);
    |                        ^   - not a struct, enum, or union
diff --git a/tests/ui/issues/issue-77218/issue-77218.fixed b/tests/ui/binding/invalid-assignment-in-while-loop-77218.fixed
similarity index 73%
rename from tests/ui/issues/issue-77218/issue-77218.fixed
rename to tests/ui/binding/invalid-assignment-in-while-loop-77218.fixed
index 6ce9dd1c2c57a..aa662ead21ac8 100644
--- a/tests/ui/issues/issue-77218/issue-77218.fixed
+++ b/tests/ui/binding/invalid-assignment-in-while-loop-77218.fixed
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/77218
 //@ run-rustfix
 fn main() {
     let value = [7u8];
diff --git a/tests/ui/issues/issue-77218/issue-77218.rs b/tests/ui/binding/invalid-assignment-in-while-loop-77218.rs
similarity index 73%
rename from tests/ui/issues/issue-77218/issue-77218.rs
rename to tests/ui/binding/invalid-assignment-in-while-loop-77218.rs
index 14edc065d0e63..9f249180e83a2 100644
--- a/tests/ui/issues/issue-77218/issue-77218.rs
+++ b/tests/ui/binding/invalid-assignment-in-while-loop-77218.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/77218
 //@ run-rustfix
 fn main() {
     let value = [7u8];
diff --git a/tests/ui/issues/issue-77218/issue-77218.stderr b/tests/ui/binding/invalid-assignment-in-while-loop-77218.stderr
similarity index 88%
rename from tests/ui/issues/issue-77218/issue-77218.stderr
rename to tests/ui/binding/invalid-assignment-in-while-loop-77218.stderr
index e98e69314d91d..e6baf349d28ad 100644
--- a/tests/ui/issues/issue-77218/issue-77218.stderr
+++ b/tests/ui/binding/invalid-assignment-in-while-loop-77218.stderr
@@ -1,5 +1,5 @@
 error[E0070]: invalid left-hand side of assignment
-  --> $DIR/issue-77218.rs:4:19
+  --> $DIR/invalid-assignment-in-while-loop-77218.rs:5:19
    |
 LL |     while Some(0) = value.get(0) {}
    |                -  ^
diff --git a/tests/ui/borrowck/borrowck-in-static.stderr b/tests/ui/borrowck/borrowck-in-static.stderr
index d85f6f5fdd5c7..32419da0ce233 100644
--- a/tests/ui/borrowck/borrowck-in-static.stderr
+++ b/tests/ui/borrowck/borrowck-in-static.stderr
@@ -10,7 +10,7 @@ LL |     Box::new(|| x)
    |              |
    |              captured by this `Fn` closure
    |
-   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
 help: consider cloning the value if the performance cost is acceptable
    |
 LL |     Box::new(|| x.clone())
diff --git a/tests/ui/borrowck/borrowck-move-by-capture.stderr b/tests/ui/borrowck/borrowck-move-by-capture.stderr
index e9e054407662f..0ace615628177 100644
--- a/tests/ui/borrowck/borrowck-move-by-capture.stderr
+++ b/tests/ui/borrowck/borrowck-move-by-capture.stderr
@@ -12,7 +12,7 @@ LL |         let _h = to_fn_once(move || -> isize { *bar });
    |                             |
    |                             `bar` is moved here
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/borrowck-move-by-capture.rs:3:37
    |
 LL | fn to_fn_mut<A:std::marker::Tuple,F:FnMut<A>>(f: F) -> F { f }
diff --git a/tests/ui/issues/issue-78192.rs b/tests/ui/borrowck/incorrect-use-after-storage-end-78192.rs
similarity index 82%
rename from tests/ui/issues/issue-78192.rs
rename to tests/ui/borrowck/incorrect-use-after-storage-end-78192.rs
index bec2a82910cfa..99a1d37eb4de7 100644
--- a/tests/ui/issues/issue-78192.rs
+++ b/tests/ui/borrowck/incorrect-use-after-storage-end-78192.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/78192
 //@ run-pass
 
 #![allow(unused_assignments)]
diff --git a/tests/ui/borrowck/issue-103624.stderr b/tests/ui/borrowck/issue-103624.stderr
index ef02280888671..bd6c1c44bfb36 100644
--- a/tests/ui/borrowck/issue-103624.stderr
+++ b/tests/ui/borrowck/issue-103624.stderr
@@ -13,7 +13,7 @@ LL |
 LL |             self.b;
    |             ^^^^^^ `self.b` is moved here
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/issue-103624.rs:7:36
    |
 LL | async fn spawn_blocking<T>(f: impl (Fn() -> T) + Send + Sync + 'static) -> T {
diff --git a/tests/ui/borrowck/issue-87456-point-to-closure.stderr b/tests/ui/borrowck/issue-87456-point-to-closure.stderr
index 043e336cd86df..c31d096109ce0 100644
--- a/tests/ui/borrowck/issue-87456-point-to-closure.stderr
+++ b/tests/ui/borrowck/issue-87456-point-to-closure.stderr
@@ -10,7 +10,7 @@ LL |
 LL |         let _foo: String = val;
    |                            ^^^ move occurs because `val` has type `String`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/issue-87456-point-to-closure.rs:3:24
    |
 LL | fn take_mut(_val: impl FnMut()) {}
diff --git a/tests/ui/issues/issue-7660.rs b/tests/ui/borrowck/rvalue-lifetime-match-equivalence-7660.rs
similarity index 88%
rename from tests/ui/issues/issue-7660.rs
rename to tests/ui/borrowck/rvalue-lifetime-match-equivalence-7660.rs
index 104cdad8f7bb7..90526de14e758 100644
--- a/tests/ui/issues/issue-7660.rs
+++ b/tests/ui/borrowck/rvalue-lifetime-match-equivalence-7660.rs
@@ -1,9 +1,9 @@
+// https://github.com/rust-lang/rust/issues/7660
 //@ run-pass
 #![allow(unused_variables)]
 // Regression test for issue 7660
 // rvalue lifetime too short when equivalent `match` works
 
-
 use std::collections::HashMap;
 
 struct A(isize, isize);
diff --git a/tests/ui/borrowck/unboxed-closures-move-upvar-from-non-once-ref-closure.stderr b/tests/ui/borrowck/unboxed-closures-move-upvar-from-non-once-ref-closure.stderr
index d33330413103f..69c3667491633 100644
--- a/tests/ui/borrowck/unboxed-closures-move-upvar-from-non-once-ref-closure.stderr
+++ b/tests/ui/borrowck/unboxed-closures-move-upvar-from-non-once-ref-closure.stderr
@@ -10,7 +10,7 @@ LL |         y.into_iter();
    |         |
    |         move occurs because `y` has type `Vec<String>`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/unboxed-closures-move-upvar-from-non-once-ref-closure.rs:5:28
    |
 LL | fn call<F>(f: F) where F : Fn() {
diff --git a/tests/ui/issues/issue-76042.rs b/tests/ui/codegen/i128-shift-overflow-check-76042.rs
similarity index 85%
rename from tests/ui/issues/issue-76042.rs
rename to tests/ui/codegen/i128-shift-overflow-check-76042.rs
index 279e860459d2c..7ae0806216cd6 100644
--- a/tests/ui/issues/issue-76042.rs
+++ b/tests/ui/codegen/i128-shift-overflow-check-76042.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/76042
 //@ run-pass
 //@ compile-flags: -Coverflow-checks=off -Ccodegen-units=1 -Copt-level=0
 
diff --git a/tests/ui/issues/issue-8248.rs b/tests/ui/coercion/mut-trait-coercion-8248.rs
similarity index 81%
rename from tests/ui/issues/issue-8248.rs
rename to tests/ui/coercion/mut-trait-coercion-8248.rs
index 95f626658cc67..a45a4d94315f1 100644
--- a/tests/ui/issues/issue-8248.rs
+++ b/tests/ui/coercion/mut-trait-coercion-8248.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8248
 //@ run-pass
 
 trait A {
diff --git a/tests/ui/issues/issue-8248.stderr b/tests/ui/coercion/mut-trait-coercion-8248.stderr
similarity index 83%
rename from tests/ui/issues/issue-8248.stderr
rename to tests/ui/coercion/mut-trait-coercion-8248.stderr
index 8570bfaefadbe..2f79a9ba1c868 100644
--- a/tests/ui/issues/issue-8248.stderr
+++ b/tests/ui/coercion/mut-trait-coercion-8248.stderr
@@ -1,5 +1,5 @@
 warning: method `dummy` is never used
-  --> $DIR/issue-8248.rs:4:8
+  --> $DIR/mut-trait-coercion-8248.rs:5:8
    |
 LL | trait A {
    |       - method in this trait
diff --git a/tests/ui/issues/issue-8398.rs b/tests/ui/coercion/mut-trait-object-coercion-8398.rs
similarity index 79%
rename from tests/ui/issues/issue-8398.rs
rename to tests/ui/coercion/mut-trait-object-coercion-8398.rs
index 7d100b855fd1a..d87d27582bab6 100644
--- a/tests/ui/issues/issue-8398.rs
+++ b/tests/ui/coercion/mut-trait-object-coercion-8398.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8398
 //@ check-pass
 #![allow(dead_code)]
 
diff --git a/tests/ui/consts/const-eval/union-const-eval-field.rs b/tests/ui/consts/const-eval/union-const-eval-field.rs
index 719e59b007c00..2c9061a7a50f8 100644
--- a/tests/ui/consts/const-eval/union-const-eval-field.rs
+++ b/tests/ui/consts/const-eval/union-const-eval-field.rs
@@ -1,5 +1,6 @@
 //@ dont-require-annotations: NOTE
 //@ normalize-stderr: "(the raw bytes of the constant) \(size: [0-9]*, align: [0-9]*\)" -> "$1 (size: $$SIZE, align: $$ALIGN)"
+//@ normalize-stderr: "([[:xdigit:]]{2}\s){4}(__\s){4}\s+│\s+([?|\.]){4}\W{4}" -> "HEX_DUMP"
 
 type Field1 = i32;
 type Field2 = f32;
diff --git a/tests/ui/consts/const-eval/union-const-eval-field.stderr b/tests/ui/consts/const-eval/union-const-eval-field.stderr
index 1843ce273ac04..3b7e5508d56c4 100644
--- a/tests/ui/consts/const-eval/union-const-eval-field.stderr
+++ b/tests/ui/consts/const-eval/union-const-eval-field.stderr
@@ -1,21 +1,21 @@
 error[E0080]: reading memory at ALLOC0[0x0..0x8], but memory is uninitialized at [0x4..0x8], and this operation requires initialized memory
-  --> $DIR/union-const-eval-field.rs:29:37
+  --> $DIR/union-const-eval-field.rs:30:37
    |
 LL |     const FIELD3: Field3 = unsafe { UNION.field3 };
    |                                     ^^^^^^^^^^^^ evaluation of `read_field3::FIELD3` failed here
    |
    = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
-               00 00 80 3f __ __ __ __                         │ ...?░░░░
+               HEX_DUMP
            }
 
 note: erroneous constant encountered
-  --> $DIR/union-const-eval-field.rs:31:5
+  --> $DIR/union-const-eval-field.rs:32:5
    |
 LL |     FIELD3
    |     ^^^^^^
 
 note: erroneous constant encountered
-  --> $DIR/union-const-eval-field.rs:31:5
+  --> $DIR/union-const-eval-field.rs:32:5
    |
 LL |     FIELD3
    |     ^^^^^^
diff --git a/tests/ui/issues/issue-76191.rs b/tests/ui/consts/const-range-matching-76191.rs
similarity index 89%
rename from tests/ui/issues/issue-76191.rs
rename to tests/ui/consts/const-range-matching-76191.rs
index d2de44380c372..b579a4b3258a7 100644
--- a/tests/ui/issues/issue-76191.rs
+++ b/tests/ui/consts/const-range-matching-76191.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/76191
 // Regression test for diagnostic issue #76191
 #![allow(non_snake_case)]
 
diff --git a/tests/ui/issues/issue-76191.stderr b/tests/ui/consts/const-range-matching-76191.stderr
similarity index 92%
rename from tests/ui/issues/issue-76191.stderr
rename to tests/ui/consts/const-range-matching-76191.stderr
index d8b54be88f4bf..5c358d0fa1cf5 100644
--- a/tests/ui/issues/issue-76191.stderr
+++ b/tests/ui/consts/const-range-matching-76191.stderr
@@ -1,11 +1,11 @@
 error[E0080]: evaluation panicked: explicit panic
-  --> $DIR/issue-76191.rs:8:37
+  --> $DIR/const-range-matching-76191.rs:9:37
    |
 LL | const RANGE2: RangeInclusive<i32> = panic!();
    |                                     ^^^^^^^^ evaluation of `RANGE2` failed here
 
 error[E0308]: mismatched types
-  --> $DIR/issue-76191.rs:14:9
+  --> $DIR/const-range-matching-76191.rs:15:9
    |
 LL | const RANGE: RangeInclusive<i32> = 0..=255;
    | -------------------------------- constant defined here
@@ -27,7 +27,7 @@ LL +         0..=255 => {}
    |
 
 error[E0308]: mismatched types
-  --> $DIR/issue-76191.rs:16:9
+  --> $DIR/const-range-matching-76191.rs:17:9
    |
 LL | const RANGE2: RangeInclusive<i32> = panic!();
    | --------------------------------- constant defined here
diff --git a/tests/ui/issues/auxiliary/issue-7899.rs b/tests/ui/cross-crate/auxiliary/aux-7899.rs
similarity index 100%
rename from tests/ui/issues/auxiliary/issue-7899.rs
rename to tests/ui/cross-crate/auxiliary/aux-7899.rs
diff --git a/tests/ui/issues/auxiliary/issue-8259.rs b/tests/ui/cross-crate/auxiliary/aux-8259.rs
similarity index 100%
rename from tests/ui/issues/auxiliary/issue-8259.rs
rename to tests/ui/cross-crate/auxiliary/aux-8259.rs
diff --git a/tests/ui/issues/issue-8259.rs b/tests/ui/cross-crate/static-regions-in-cross-crate-8259.rs
similarity index 55%
rename from tests/ui/issues/issue-8259.rs
rename to tests/ui/cross-crate/static-regions-in-cross-crate-8259.rs
index e843f7f9c5083..347cfa2aee130 100644
--- a/tests/ui/issues/issue-8259.rs
+++ b/tests/ui/cross-crate/static-regions-in-cross-crate-8259.rs
@@ -1,11 +1,11 @@
+// https://github.com/rust-lang/rust/issues/8259
 //@ run-pass
 #![allow(dead_code)]
 #![allow(non_upper_case_globals)]
 
-//@ aux-build:issue-8259.rs
+//@ aux-build:aux-8259.rs
 
-
-extern crate issue_8259 as other;
+extern crate aux_8259 as other;
 static a: other::Foo<'static> = other::Foo::A;
 
 pub fn main() {}
diff --git a/tests/ui/cross-crate/tuple-like-structs-cross-crate-7899.rs b/tests/ui/cross-crate/tuple-like-structs-cross-crate-7899.rs
new file mode 100644
index 0000000000000..ce3ea7dd5796a
--- /dev/null
+++ b/tests/ui/cross-crate/tuple-like-structs-cross-crate-7899.rs
@@ -0,0 +1,10 @@
+// https://github.com/rust-lang/rust/issues/7899
+//@ run-pass
+#![allow(unused_variables)]
+//@ aux-build:aux-7899.rs
+
+extern crate aux_7899 as testcrate;
+
+fn main() {
+    let f = testcrate::V2(1.0f32, 2.0f32);
+}
diff --git a/tests/ui/issues/auxiliary/issue-8401.rs b/tests/ui/dyn-keyword/auxiliary/aux-8401.rs
similarity index 100%
rename from tests/ui/issues/auxiliary/issue-8401.rs
rename to tests/ui/dyn-keyword/auxiliary/aux-8401.rs
diff --git a/tests/ui/dyn-keyword/methods-with-mut-trait-and-polymorphic-objects-issue-8401.rs b/tests/ui/dyn-keyword/methods-with-mut-trait-and-polymorphic-objects-issue-8401.rs
new file mode 100644
index 0000000000000..313c6891720ac
--- /dev/null
+++ b/tests/ui/dyn-keyword/methods-with-mut-trait-and-polymorphic-objects-issue-8401.rs
@@ -0,0 +1,7 @@
+//@ run-pass
+//@ aux-build:aux-8401.rs
+// https://github.com/rust-lang/rust/issues/8401
+
+extern crate aux_8401;
+
+pub fn main() {}
diff --git a/tests/ui/issues/issue-8761.rs b/tests/ui/enum/enum-discriminant-type-mismatch-8761.rs
similarity index 80%
rename from tests/ui/issues/issue-8761.rs
rename to tests/ui/enum/enum-discriminant-type-mismatch-8761.rs
index 5883bb9669562..ae09b919dc152 100644
--- a/tests/ui/issues/issue-8761.rs
+++ b/tests/ui/enum/enum-discriminant-type-mismatch-8761.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8761
 enum Foo {
     A = 1i64,
     //~^ ERROR mismatched types
diff --git a/tests/ui/issues/issue-8761.stderr b/tests/ui/enum/enum-discriminant-type-mismatch-8761.stderr
similarity index 83%
rename from tests/ui/issues/issue-8761.stderr
rename to tests/ui/enum/enum-discriminant-type-mismatch-8761.stderr
index 4a9db56891386..f1645183e176b 100644
--- a/tests/ui/issues/issue-8761.stderr
+++ b/tests/ui/enum/enum-discriminant-type-mismatch-8761.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-8761.rs:2:9
+  --> $DIR/enum-discriminant-type-mismatch-8761.rs:3:9
    |
 LL |     A = 1i64,
    |         ^^^^ expected `isize`, found `i64`
@@ -11,7 +11,7 @@ LL +     A = 1isize,
    |
 
 error[E0308]: mismatched types
-  --> $DIR/issue-8761.rs:5:9
+  --> $DIR/enum-discriminant-type-mismatch-8761.rs:6:9
    |
 LL |     B = 2u8
    |         ^^^ expected `isize`, found `u8`
diff --git a/tests/ui/issues/issue-80607.rs b/tests/ui/enum/enum-variant-field-error-80607.rs
similarity index 82%
rename from tests/ui/issues/issue-80607.rs
rename to tests/ui/enum/enum-variant-field-error-80607.rs
index 63f4df359b831..aa3f2f7c526f6 100644
--- a/tests/ui/issues/issue-80607.rs
+++ b/tests/ui/enum/enum-variant-field-error-80607.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/80607
 // This tests makes sure the diagnostics print the offending enum variant, not just the type.
 pub enum Enum {
     V1(i32),
diff --git a/tests/ui/issues/issue-80607.stderr b/tests/ui/enum/enum-variant-field-error-80607.stderr
similarity index 89%
rename from tests/ui/issues/issue-80607.stderr
rename to tests/ui/enum/enum-variant-field-error-80607.stderr
index 8f9f494c8b7a4..8d088ef04bbbf 100644
--- a/tests/ui/issues/issue-80607.stderr
+++ b/tests/ui/enum/enum-variant-field-error-80607.stderr
@@ -1,5 +1,5 @@
 error[E0559]: variant `Enum::V1` has no field named `x`
-  --> $DIR/issue-80607.rs:7:16
+  --> $DIR/enum-variant-field-error-80607.rs:8:16
    |
 LL |     V1(i32),
    |     -- `Enum::V1` defined here
diff --git a/tests/ui/issues/issue-8506.rs b/tests/ui/enum/simple-enum-usage-8506.rs
similarity index 78%
rename from tests/ui/issues/issue-8506.rs
rename to tests/ui/enum/simple-enum-usage-8506.rs
index 30a789a3e27bf..ebe095d84e437 100644
--- a/tests/ui/issues/issue-8506.rs
+++ b/tests/ui/enum/simple-enum-usage-8506.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8506
 //@ run-pass
 #![allow(non_upper_case_globals)]
 
diff --git a/tests/ui/issues/issue-75283.rs b/tests/ui/extern/function-definition-in-extern-block-75283.rs
similarity index 70%
rename from tests/ui/issues/issue-75283.rs
rename to tests/ui/extern/function-definition-in-extern-block-75283.rs
index d556132e47ffd..e2b7358743ba1 100644
--- a/tests/ui/issues/issue-75283.rs
+++ b/tests/ui/extern/function-definition-in-extern-block-75283.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/75283
 extern "C" {
     fn lol() { //~ ERROR incorrect function inside `extern` block
         println!("");
diff --git a/tests/ui/issues/issue-75283.stderr b/tests/ui/extern/function-definition-in-extern-block-75283.stderr
similarity index 91%
rename from tests/ui/issues/issue-75283.stderr
rename to tests/ui/extern/function-definition-in-extern-block-75283.stderr
index 240d9716a5561..67be1c2959922 100644
--- a/tests/ui/issues/issue-75283.stderr
+++ b/tests/ui/extern/function-definition-in-extern-block-75283.stderr
@@ -1,5 +1,5 @@
 error: incorrect function inside `extern` block
-  --> $DIR/issue-75283.rs:2:8
+  --> $DIR/function-definition-in-extern-block-75283.rs:3:8
    |
 LL |   extern "C" {
    |   ---------- `extern` blocks define existing foreign functions and functions inside of them cannot have a body
diff --git a/tests/ui/issues/issue-86756.rs b/tests/ui/generics/duplicate-generic-parameter-error-86756.rs
similarity index 89%
rename from tests/ui/issues/issue-86756.rs
rename to tests/ui/generics/duplicate-generic-parameter-error-86756.rs
index 55a6c144839e8..acc281cb8c456 100644
--- a/tests/ui/issues/issue-86756.rs
+++ b/tests/ui/generics/duplicate-generic-parameter-error-86756.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/86756
 //@ edition: 2015
 trait Foo<T, T = T> {}
 //~^ ERROR the name `T` is already used for a generic parameter in this item's generic parameters
diff --git a/tests/ui/issues/issue-86756.stderr b/tests/ui/generics/duplicate-generic-parameter-error-86756.stderr
similarity index 82%
rename from tests/ui/issues/issue-86756.stderr
rename to tests/ui/generics/duplicate-generic-parameter-error-86756.stderr
index b650b32c2a367..d4b2169ffd2dd 100644
--- a/tests/ui/issues/issue-86756.stderr
+++ b/tests/ui/generics/duplicate-generic-parameter-error-86756.stderr
@@ -1,5 +1,5 @@
 error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
-  --> $DIR/issue-86756.rs:2:14
+  --> $DIR/duplicate-generic-parameter-error-86756.rs:3:14
    |
 LL | trait Foo<T, T = T> {}
    |           -  ^ already used
@@ -7,13 +7,13 @@ LL | trait Foo<T, T = T> {}
    |           first use of `T`
 
 error[E0412]: cannot find type `dyn` in this scope
-  --> $DIR/issue-86756.rs:6:10
+  --> $DIR/duplicate-generic-parameter-error-86756.rs:7:10
    |
 LL |     eq::<dyn, Foo>
    |          ^^^ not found in this scope
 
 warning: trait objects without an explicit `dyn` are deprecated
-  --> $DIR/issue-86756.rs:6:15
+  --> $DIR/duplicate-generic-parameter-error-86756.rs:7:15
    |
 LL |     eq::<dyn, Foo>
    |               ^^^
@@ -27,13 +27,13 @@ LL |     eq::<dyn, dyn Foo>
    |               +++
 
 error[E0107]: missing generics for trait `Foo`
-  --> $DIR/issue-86756.rs:6:15
+  --> $DIR/duplicate-generic-parameter-error-86756.rs:7:15
    |
 LL |     eq::<dyn, Foo>
    |               ^^^ expected at least 1 generic argument
    |
 note: trait defined here, with at least 1 generic parameter: `T`
-  --> $DIR/issue-86756.rs:2:7
+  --> $DIR/duplicate-generic-parameter-error-86756.rs:3:7
    |
 LL | trait Foo<T, T = T> {}
    |       ^^^ -
diff --git a/tests/ui/issues/issue-85461.rs b/tests/ui/instrument-coverage/link-regex-crate-with-instrument-coverage-85461.rs
similarity index 91%
rename from tests/ui/issues/issue-85461.rs
rename to tests/ui/instrument-coverage/link-regex-crate-with-instrument-coverage-85461.rs
index 72538081ccb3a..ffb535e69ee56 100644
--- a/tests/ui/issues/issue-85461.rs
+++ b/tests/ui/instrument-coverage/link-regex-crate-with-instrument-coverage-85461.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/85461
 //@ compile-flags: -Cinstrument-coverage -Ccodegen-units=4 --crate-type dylib -Copt-level=0
 //@ build-pass
 //@ needs-profiler-runtime
diff --git a/tests/ui/intrinsics/intrinsic-raw_eq-const-bad.rs b/tests/ui/intrinsics/intrinsic-raw_eq-const-bad.rs
index 15f4a9a778ed6..ed15f5bba9622 100644
--- a/tests/ui/intrinsics/intrinsic-raw_eq-const-bad.rs
+++ b/tests/ui/intrinsics/intrinsic-raw_eq-const-bad.rs
@@ -1,3 +1,4 @@
+//@ normalize-stderr: "[[:xdigit:]]{2} __ ([[:xdigit:]]{2}\s){2}" -> "HEX_DUMP"
 #![feature(core_intrinsics)]
 
 const RAW_EQ_PADDING: bool = unsafe {
diff --git a/tests/ui/intrinsics/intrinsic-raw_eq-const-bad.stderr b/tests/ui/intrinsics/intrinsic-raw_eq-const-bad.stderr
index 5f4ef14d58697..329da35297e1c 100644
--- a/tests/ui/intrinsics/intrinsic-raw_eq-const-bad.stderr
+++ b/tests/ui/intrinsics/intrinsic-raw_eq-const-bad.stderr
@@ -1,15 +1,15 @@
 error[E0080]: reading memory at ALLOC0[0x0..0x4], but memory is uninitialized at [0x1..0x2], and this operation requires initialized memory
-  --> $DIR/intrinsic-raw_eq-const-bad.rs:4:5
+  --> $DIR/intrinsic-raw_eq-const-bad.rs:5:5
    |
 LL |     std::intrinsics::raw_eq(&(1_u8, 2_u16), &(1_u8, 2_u16))
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `RAW_EQ_PADDING` failed here
    |
    = note: the raw bytes of the constant (size: 4, align: 2) {
-               01 __ 02 00                                     │ .░..
+               HEX_DUMP                                    │ .░..
            }
 
 error[E0080]: unable to turn pointer into integer
-  --> $DIR/intrinsic-raw_eq-const-bad.rs:9:5
+  --> $DIR/intrinsic-raw_eq-const-bad.rs:10:5
    |
 LL |     std::intrinsics::raw_eq(&(&0), &(&1))
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `RAW_EQ_PTR` failed here
@@ -18,7 +18,7 @@ LL |     std::intrinsics::raw_eq(&(&0), &(&1))
    = help: the absolute address of a pointer is not known at compile-time, so such operations are not supported
 
 error[E0080]: accessing memory with alignment 1, but alignment 4 is required
-  --> $DIR/intrinsic-raw_eq-const-bad.rs:16:5
+  --> $DIR/intrinsic-raw_eq-const-bad.rs:17:5
    |
 LL |     std::intrinsics::raw_eq(aref, aref)
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `RAW_EQ_NOT_ALIGNED` failed here
diff --git a/tests/ui/issues/issue-4335.stderr b/tests/ui/issues/issue-4335.stderr
index b6d8f08616383..d1a64e3dd4620 100644
--- a/tests/ui/issues/issue-4335.stderr
+++ b/tests/ui/issues/issue-4335.stderr
@@ -10,7 +10,7 @@ LL |     id(Box::new(|| *v))
    |                 |
    |                 captured by this `FnMut` closure
    |
-   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
 help: if `T` implemented `Clone`, you could clone the value
   --> $DIR/issue-4335.rs:5:10
    |
diff --git a/tests/ui/issues/issue-77218/issue-77218-2.fixed b/tests/ui/issues/issue-77218/issue-77218-2.fixed
deleted file mode 100644
index 98d79b5da6561..0000000000000
--- a/tests/ui/issues/issue-77218/issue-77218-2.fixed
+++ /dev/null
@@ -1,6 +0,0 @@
-//@ run-rustfix
-fn main() {
-    let value = [7u8];
-    while let Some(0) = value.get(0) { //~ ERROR invalid left-hand side of assignment
-    }
-}
diff --git a/tests/ui/issues/issue-77218/issue-77218-2.rs b/tests/ui/issues/issue-77218/issue-77218-2.rs
deleted file mode 100644
index 3be38f8f721da..0000000000000
--- a/tests/ui/issues/issue-77218/issue-77218-2.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-//@ run-rustfix
-fn main() {
-    let value = [7u8];
-    while Some(0) = value.get(0) { //~ ERROR invalid left-hand side of assignment
-    }
-}
diff --git a/tests/ui/issues/issue-77218/issue-77218-2.stderr b/tests/ui/issues/issue-77218/issue-77218-2.stderr
deleted file mode 100644
index dfed0b6e67e33..0000000000000
--- a/tests/ui/issues/issue-77218/issue-77218-2.stderr
+++ /dev/null
@@ -1,16 +0,0 @@
-error[E0070]: invalid left-hand side of assignment
-  --> $DIR/issue-77218-2.rs:4:19
-   |
-LL |     while Some(0) = value.get(0) {
-   |                -  ^
-   |                |
-   |                cannot assign to this expression
-   |
-help: you might have meant to use pattern destructuring
-   |
-LL |     while let Some(0) = value.get(0) {
-   |           +++
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0070`.
diff --git a/tests/ui/issues/issue-7899.rs b/tests/ui/issues/issue-7899.rs
deleted file mode 100644
index 4b69f3e3d89aa..0000000000000
--- a/tests/ui/issues/issue-7899.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-//@ run-pass
-#![allow(unused_variables)]
-//@ aux-build:issue-7899.rs
-
-
-extern crate issue_7899 as testcrate;
-
-fn main() {
-    let f = testcrate::V2(1.0f32, 2.0f32);
-}
diff --git a/tests/ui/issues/issue-8044.rs b/tests/ui/issues/issue-8044.rs
deleted file mode 100644
index 3c10bbca6342b..0000000000000
--- a/tests/ui/issues/issue-8044.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-//@ run-pass
-//@ aux-build:issue-8044.rs
-
-
-extern crate issue_8044 as minimal;
-use minimal::{BTree, leaf};
-
-pub fn main() {
-    BTree::<isize> { node: leaf(1) };
-}
diff --git a/tests/ui/issues/issue-8401.rs b/tests/ui/issues/issue-8401.rs
deleted file mode 100644
index 1df63516fb0be..0000000000000
--- a/tests/ui/issues/issue-8401.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-//@ run-pass
-//@ aux-build:issue-8401.rs
-
-
-extern crate issue_8401;
-
-pub fn main() {}
diff --git a/tests/ui/issues/issue-9123.rs b/tests/ui/issues/issue-9123.rs
deleted file mode 100644
index bbf6c13341c27..0000000000000
--- a/tests/ui/issues/issue-9123.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-//@ run-pass
-//@ aux-build:issue-9123.rs
-
-
-extern crate issue_9123;
-
-pub fn main() {}
diff --git a/tests/ui/issues/issue-81584.fixed b/tests/ui/iterators/iterator-scope-collect-suggestion-81584.fixed
similarity index 84%
rename from tests/ui/issues/issue-81584.fixed
rename to tests/ui/iterators/iterator-scope-collect-suggestion-81584.fixed
index c3d33a1b4f8bc..0e3d48fe27d8a 100644
--- a/tests/ui/issues/issue-81584.fixed
+++ b/tests/ui/iterators/iterator-scope-collect-suggestion-81584.fixed
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/81584
 //@ run-rustfix
 fn main() {
         let _ = vec![vec![0, 1], vec![2]]
diff --git a/tests/ui/issues/issue-81584.rs b/tests/ui/iterators/iterator-scope-collect-suggestion-81584.rs
similarity index 83%
rename from tests/ui/issues/issue-81584.rs
rename to tests/ui/iterators/iterator-scope-collect-suggestion-81584.rs
index 27db73aaa2c86..3fba39517fcc5 100644
--- a/tests/ui/issues/issue-81584.rs
+++ b/tests/ui/iterators/iterator-scope-collect-suggestion-81584.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/81584
 //@ run-rustfix
 fn main() {
         let _ = vec![vec![0, 1], vec![2]]
diff --git a/tests/ui/issues/issue-81584.stderr b/tests/ui/iterators/iterator-scope-collect-suggestion-81584.stderr
similarity index 89%
rename from tests/ui/issues/issue-81584.stderr
rename to tests/ui/iterators/iterator-scope-collect-suggestion-81584.stderr
index eb97916ad75ef..e180183e7e387 100644
--- a/tests/ui/issues/issue-81584.stderr
+++ b/tests/ui/iterators/iterator-scope-collect-suggestion-81584.stderr
@@ -1,5 +1,5 @@
 error[E0515]: cannot return value referencing function parameter `y`
-  --> $DIR/issue-81584.rs:5:22
+  --> $DIR/iterator-scope-collect-suggestion-81584.rs:6:22
    |
 LL |             .map(|y| y.iter().map(|x| x + 1))
    |                      -^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/macros/cfg_select.rs b/tests/ui/macros/cfg_select.rs
index 461d2e0e8c1f5..9241141ef9a6c 100644
--- a/tests/ui/macros/cfg_select.rs
+++ b/tests/ui/macros/cfg_select.rs
@@ -8,10 +8,42 @@ fn print() {
     });
 }
 
-fn arm_rhs_must_be_in_braces() -> i32 {
+fn print_2() {
+    println!(cfg_select! {
+        unix => "unix",
+        _ => "not unix",
+    });
+}
+
+fn arm_rhs_expr_1() -> i32 {
     cfg_select! {
         true => 1
-        //~^ ERROR: expected `{`, found `1`
+    }
+}
+
+fn arm_rhs_expr_2() -> i32 {
+    cfg_select! {
+        true => 1,
+        false => 2
+    }
+}
+
+fn arm_rhs_expr_3() -> i32 {
+    cfg_select! {
+        true => 1,
+        false => 2,
+        true => { 42 }
+        false => -1 as i32,
+        true => 2 + 2,
+        false => "",
+        true => if true { 42 } else { 84 }
+        false => if true { 42 } else { 84 },
+        true => return 42,
+        false => loop {}
+        true => (1, 2),
+        false => (1, 2,),
+        true => todo!(),
+        false => println!("hello"),
     }
 }
 
diff --git a/tests/ui/macros/cfg_select.stderr b/tests/ui/macros/cfg_select.stderr
index 6c18a7c189dcc..7280f35c16f93 100644
--- a/tests/ui/macros/cfg_select.stderr
+++ b/tests/ui/macros/cfg_select.stderr
@@ -1,11 +1,5 @@
-error: expected `{`, found `1`
-  --> $DIR/cfg_select.rs:13:17
-   |
-LL |         true => 1
-   |                 ^ expected `{`
-
 warning: unreachable predicate
-  --> $DIR/cfg_select.rs:20:5
+  --> $DIR/cfg_select.rs:52:5
    |
 LL |     _ => {}
    |     - always matches
@@ -13,7 +7,7 @@ LL |     true => {}
    |     ^^^^ this predicate is never reached
 
 error: none of the predicates in this `cfg_select` evaluated to true
-  --> $DIR/cfg_select.rs:24:1
+  --> $DIR/cfg_select.rs:56:1
    |
 LL | / cfg_select! {
 LL | |
@@ -22,10 +16,10 @@ LL | | }
    | |_^
 
 error: none of the predicates in this `cfg_select` evaluated to true
-  --> $DIR/cfg_select.rs:29:1
+  --> $DIR/cfg_select.rs:61:1
    |
 LL | cfg_select! {}
    | ^^^^^^^^^^^^^^
 
-error: aborting due to 3 previous errors; 1 warning emitted
+error: aborting due to 2 previous errors; 1 warning emitted
 
diff --git a/tests/ui/issues/issue-7970a.rs b/tests/ui/macros/macro-invocation-span-error-7970.rs
similarity index 51%
rename from tests/ui/issues/issue-7970a.rs
rename to tests/ui/macros/macro-invocation-span-error-7970.rs
index dae906410ed61..df7e1cfea88bc 100644
--- a/tests/ui/issues/issue-7970a.rs
+++ b/tests/ui/macros/macro-invocation-span-error-7970.rs
@@ -1,5 +1,8 @@
+// https://github.com/rust-lang/rust/issues/7970
 macro_rules! one_arg_macro {
-    ($fmt:expr) => (print!(concat!($fmt, "\n")));
+    ($fmt:expr) => {
+        print!(concat!($fmt, "\n"))
+    };
 }
 
 fn main() {
diff --git a/tests/ui/issues/issue-7970a.stderr b/tests/ui/macros/macro-invocation-span-error-7970.stderr
similarity index 73%
rename from tests/ui/issues/issue-7970a.stderr
rename to tests/ui/macros/macro-invocation-span-error-7970.stderr
index 1e6bb92ea579e..beb54e0599248 100644
--- a/tests/ui/issues/issue-7970a.stderr
+++ b/tests/ui/macros/macro-invocation-span-error-7970.stderr
@@ -1,5 +1,5 @@
 error: unexpected end of macro invocation
-  --> $DIR/issue-7970a.rs:6:5
+  --> $DIR/macro-invocation-span-error-7970.rs:9:5
    |
 LL | macro_rules! one_arg_macro {
    | -------------------------- when calling this macro
@@ -8,9 +8,9 @@ LL |     one_arg_macro!();
    |     ^^^^^^^^^^^^^^^^ missing tokens in macro arguments
    |
 note: while trying to match meta-variable `$fmt:expr`
-  --> $DIR/issue-7970a.rs:2:6
+  --> $DIR/macro-invocation-span-error-7970.rs:3:6
    |
-LL |     ($fmt:expr) => (print!(concat!($fmt, "\n")));
+LL |     ($fmt:expr) => {
    |      ^^^^^^^^^
 
 error: aborting due to 1 previous error
diff --git a/tests/ui/issues/issue-8521.rs b/tests/ui/macros/macro-path-type-bounds-8521.rs
similarity index 84%
rename from tests/ui/issues/issue-8521.rs
rename to tests/ui/macros/macro-path-type-bounds-8521.rs
index 78ce85787d5cf..975d3dc402e1f 100644
--- a/tests/ui/issues/issue-8521.rs
+++ b/tests/ui/macros/macro-path-type-bounds-8521.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8521
 //@ check-pass
 trait Foo1 {}
 
diff --git a/tests/ui/issues/issue-7911.rs b/tests/ui/macros/macro-self-mutability-7911.rs
similarity index 95%
rename from tests/ui/issues/issue-7911.rs
rename to tests/ui/macros/macro-self-mutability-7911.rs
index 11da4df5285f1..5313f86d97f5f 100644
--- a/tests/ui/issues/issue-7911.rs
+++ b/tests/ui/macros/macro-self-mutability-7911.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/7911
 //@ run-pass
 // (Closes #7911) Test that we can use the same self expression
 // with different mutability in macro in two methods
diff --git a/tests/ui/issues/issue-7911.stderr b/tests/ui/macros/macro-self-mutability-7911.stderr
similarity index 83%
rename from tests/ui/issues/issue-7911.stderr
rename to tests/ui/macros/macro-self-mutability-7911.stderr
index ead7ee191ac9b..7fc2abe06eb39 100644
--- a/tests/ui/issues/issue-7911.stderr
+++ b/tests/ui/macros/macro-self-mutability-7911.stderr
@@ -1,5 +1,5 @@
 warning: method `dummy` is never used
-  --> $DIR/issue-7911.rs:7:8
+  --> $DIR/macro-self-mutability-7911.rs:8:8
    |
 LL | trait FooBar {
    |       ------ method in this trait
diff --git a/tests/ui/issues/issue-7867.rs b/tests/ui/match/mismatched-types-in-match-pattern-7867.rs
similarity index 87%
rename from tests/ui/issues/issue-7867.rs
rename to tests/ui/match/mismatched-types-in-match-pattern-7867.rs
index 87e7c831e6855..9ff8755c81956 100644
--- a/tests/ui/issues/issue-7867.rs
+++ b/tests/ui/match/mismatched-types-in-match-pattern-7867.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/7867
 //@ dont-require-annotations: NOTE
 
 enum A { B, C }
diff --git a/tests/ui/issues/issue-7867.stderr b/tests/ui/match/mismatched-types-in-match-pattern-7867.stderr
similarity index 88%
rename from tests/ui/issues/issue-7867.stderr
rename to tests/ui/match/mismatched-types-in-match-pattern-7867.stderr
index fcb69d775face..8997f36114a89 100644
--- a/tests/ui/issues/issue-7867.stderr
+++ b/tests/ui/match/mismatched-types-in-match-pattern-7867.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-7867.rs:9:9
+  --> $DIR/mismatched-types-in-match-pattern-7867.rs:10:9
    |
 LL | enum A { B, C }
    |          - unit variant defined here
diff --git a/tests/ui/issues/issue-7575.rs b/tests/ui/methods/trait-method-self-param-error-7575.rs
similarity index 83%
rename from tests/ui/issues/issue-7575.rs
rename to tests/ui/methods/trait-method-self-param-error-7575.rs
index 8b1fdf6c851e2..9793d43cc24fc 100644
--- a/tests/ui/issues/issue-7575.rs
+++ b/tests/ui/methods/trait-method-self-param-error-7575.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/7575
 //@ run-pass
 
 trait Foo { //~ WARN trait `Foo` is never used
diff --git a/tests/ui/issues/issue-7575.stderr b/tests/ui/methods/trait-method-self-param-error-7575.stderr
similarity index 74%
rename from tests/ui/issues/issue-7575.stderr
rename to tests/ui/methods/trait-method-self-param-error-7575.stderr
index 2f987d19c80ce..5c10a7e1da9d0 100644
--- a/tests/ui/issues/issue-7575.stderr
+++ b/tests/ui/methods/trait-method-self-param-error-7575.stderr
@@ -1,5 +1,5 @@
 warning: trait `Foo` is never used
-  --> $DIR/issue-7575.rs:3:7
+  --> $DIR/trait-method-self-param-error-7575.rs:4:7
    |
 LL | trait Foo {
    |       ^^^
diff --git a/tests/ui/issues/issue-81918.rs b/tests/ui/mir/mir-cfg-unpretty-check-81918.rs
similarity index 81%
rename from tests/ui/issues/issue-81918.rs
rename to tests/ui/mir/mir-cfg-unpretty-check-81918.rs
index ee9721c2493de..4798a6543755d 100644
--- a/tests/ui/issues/issue-81918.rs
+++ b/tests/ui/mir/mir-cfg-unpretty-check-81918.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/81918
 //@ check-pass
 //@ dont-check-compiler-stdout
 //@ compile-flags: -Z unpretty=mir-cfg
diff --git a/tests/ui/issues/issue-87490.rs b/tests/ui/mismatched_types/mismatched-types-in-trait-implementation-87490.rs
similarity index 80%
rename from tests/ui/issues/issue-87490.rs
rename to tests/ui/mismatched_types/mismatched-types-in-trait-implementation-87490.rs
index 998f61a6bd32d..67e16ec6ce3ab 100644
--- a/tests/ui/issues/issue-87490.rs
+++ b/tests/ui/mismatched_types/mismatched-types-in-trait-implementation-87490.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/87490
 fn main() {}
 trait StreamOnce {
     type Position;
diff --git a/tests/ui/issues/issue-87490.stderr b/tests/ui/mismatched_types/mismatched-types-in-trait-implementation-87490.stderr
similarity index 87%
rename from tests/ui/issues/issue-87490.stderr
rename to tests/ui/mismatched_types/mismatched-types-in-trait-implementation-87490.stderr
index 5a4ec55833bea..bbd73347d0272 100644
--- a/tests/ui/issues/issue-87490.stderr
+++ b/tests/ui/mismatched_types/mismatched-types-in-trait-implementation-87490.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-87490.rs:9:5
+  --> $DIR/mismatched-types-in-trait-implementation-87490.rs:10:5
    |
 LL | fn follow(_: &str) -> <&str as StreamOnce>::Position {
    |                       ------------------------------ expected `usize` because of return type
diff --git a/tests/ui/moves/moves-based-on-type-move-out-of-closure-env-issue-1965.stderr b/tests/ui/moves/moves-based-on-type-move-out-of-closure-env-issue-1965.stderr
index dfc983bf48744..e2aa5718cb650 100644
--- a/tests/ui/moves/moves-based-on-type-move-out-of-closure-env-issue-1965.stderr
+++ b/tests/ui/moves/moves-based-on-type-move-out-of-closure-env-issue-1965.stderr
@@ -10,7 +10,7 @@ LL |     let _f = to_fn(|| test(i));
    |                    |
    |                    captured by this `Fn` closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/moves-based-on-type-move-out-of-closure-env-issue-1965.rs:3:33
    |
 LL | fn to_fn<A:std::marker::Tuple,F:Fn<A>>(f: F) -> F { f }
diff --git a/tests/ui/nll/issue-52663-span-decl-captured-variable.stderr b/tests/ui/nll/issue-52663-span-decl-captured-variable.stderr
index 7f9a8e50dae66..4749e3b8e453d 100644
--- a/tests/ui/nll/issue-52663-span-decl-captured-variable.stderr
+++ b/tests/ui/nll/issue-52663-span-decl-captured-variable.stderr
@@ -10,7 +10,7 @@ LL |        expect_fn(|| drop(x.0));
    |                  |
    |                  captured by this `Fn` closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/issue-52663-span-decl-captured-variable.rs:1:33
    |
 LL | fn expect_fn<F>(f: F) where F : Fn() {
diff --git a/tests/ui/or-patterns/issue-64879-trailing-before-guard.fixed b/tests/ui/or-patterns/issue-64879-trailing-before-guard.fixed
new file mode 100644
index 0000000000000..0c65f709d6636
--- /dev/null
+++ b/tests/ui/or-patterns/issue-64879-trailing-before-guard.fixed
@@ -0,0 +1,18 @@
+// In this regression test we check that a trailing `|` in an or-pattern just
+// before the `if` token of a `match` guard will receive parser recovery with
+// an appropriate error message.
+//@ run-rustfix
+#![allow(dead_code)]
+
+enum E { A, B }
+
+fn main() {
+    match E::A {
+        E::A |
+        E::B //~ ERROR a trailing `|` is not allowed in an or-pattern
+        if true => {
+            let _recovery_witness: i32 = 0i32; //~ ERROR mismatched types
+        }
+        _ => {}
+    }
+}
diff --git a/tests/ui/or-patterns/issue-64879-trailing-before-guard.rs b/tests/ui/or-patterns/issue-64879-trailing-before-guard.rs
index 181c770096a5f..d7da564c2e1d6 100644
--- a/tests/ui/or-patterns/issue-64879-trailing-before-guard.rs
+++ b/tests/ui/or-patterns/issue-64879-trailing-before-guard.rs
@@ -1,6 +1,8 @@
 // In this regression test we check that a trailing `|` in an or-pattern just
 // before the `if` token of a `match` guard will receive parser recovery with
 // an appropriate error message.
+//@ run-rustfix
+#![allow(dead_code)]
 
 enum E { A, B }
 
@@ -9,7 +11,8 @@ fn main() {
         E::A |
         E::B | //~ ERROR a trailing `|` is not allowed in an or-pattern
         if true => {
-            let recovery_witness: bool = 0; //~ ERROR mismatched types
+            let _recovery_witness: i32 = 0u32; //~ ERROR mismatched types
         }
+        _ => {}
     }
 }
diff --git a/tests/ui/or-patterns/issue-64879-trailing-before-guard.stderr b/tests/ui/or-patterns/issue-64879-trailing-before-guard.stderr
index 91db3d049f629..238c76080dc4f 100644
--- a/tests/ui/or-patterns/issue-64879-trailing-before-guard.stderr
+++ b/tests/ui/or-patterns/issue-64879-trailing-before-guard.stderr
@@ -1,24 +1,24 @@
 error: a trailing `|` is not allowed in an or-pattern
-  --> $DIR/issue-64879-trailing-before-guard.rs:10:14
+  --> $DIR/issue-64879-trailing-before-guard.rs:12:14
    |
 LL |         E::A |
    |         ---- while parsing this or-pattern starting here
 LL |         E::B |
    |              ^
+
+error[E0308]: mismatched types
+  --> $DIR/issue-64879-trailing-before-guard.rs:14:42
    |
-help: remove the `|`
+LL |             let _recovery_witness: i32 = 0u32;
+   |                                    ---   ^^^^ expected `i32`, found `u32`
+   |                                    |
+   |                                    expected due to this
    |
-LL -         E::B |
-LL +         E::B
+help: change the type of the numeric literal from `u32` to `i32`
    |
-
-error[E0308]: mismatched types
-  --> $DIR/issue-64879-trailing-before-guard.rs:12:42
+LL -             let _recovery_witness: i32 = 0u32;
+LL +             let _recovery_witness: i32 = 0i32;
    |
-LL |             let recovery_witness: bool = 0;
-   |                                   ----   ^ expected `bool`, found integer
-   |                                   |
-   |                                   expected due to this
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/or-patterns/remove-leading-vert.fixed b/tests/ui/or-patterns/remove-leading-vert.fixed
index 2851b8f18c54a..aa7975dc508aa 100644
--- a/tests/ui/or-patterns/remove-leading-vert.fixed
+++ b/tests/ui/or-patterns/remove-leading-vert.fixed
@@ -23,26 +23,26 @@ fn leading() {
 
 #[cfg(false)]
 fn trailing() {
-    let ( A  ): E; //~ ERROR a trailing `|` is not allowed in an or-pattern
-    let (a ,): (E,); //~ ERROR a trailing `|` is not allowed in an or-pattern
-    let ( A | B  ): E; //~ ERROR a trailing `|` is not allowed in an or-pattern
-    let [ A | B  ]: [E; 1]; //~ ERROR a trailing `|` is not allowed in an or-pattern
-    let S { f: B  }; //~ ERROR a trailing `|` is not allowed in an or-pattern
-    let ( A | B  ): E; //~ ERROR unexpected token `||` in pattern
+    let ( A ): E; //~ ERROR a trailing `|` is not allowed in an or-pattern
+    let (a,): (E,); //~ ERROR a trailing `|` is not allowed in an or-pattern
+    let ( A | B ): E; //~ ERROR a trailing `|` is not allowed in an or-pattern
+    let [ A | B ]: [E; 1]; //~ ERROR a trailing `|` is not allowed in an or-pattern
+    let S { f: B }; //~ ERROR a trailing `|` is not allowed in an or-pattern
+    let ( A | B ): E; //~ ERROR unexpected token `||` in pattern
     //~^ ERROR a trailing `|` is not allowed in an or-pattern
     match A {
-        A  => {} //~ ERROR a trailing `|` is not allowed in an or-pattern
-        A  => {} //~ ERROR a trailing `|` is not allowed in an or-pattern
-        A | B  => {} //~ ERROR unexpected token `||` in pattern
+        A => {} //~ ERROR a trailing `|` is not allowed in an or-pattern
+        A => {} //~ ERROR a trailing `||` is not allowed in an or-pattern
+        A | B => {} //~ ERROR unexpected token `||` in pattern
         //~^ ERROR a trailing `|` is not allowed in an or-pattern
-        | A | B  => {}
+        | A | B => {}
         //~^ ERROR a trailing `|` is not allowed in an or-pattern
     }
 
     // These test trailing-vert in `let` bindings, but they also test that we don't emit a
     // duplicate suggestion that would confuse rustfix.
 
-    let a  : u8 = 0; //~ ERROR a trailing `|` is not allowed in an or-pattern
-    let a  = 0; //~ ERROR a trailing `|` is not allowed in an or-pattern
-    let a  ; //~ ERROR a trailing `|` is not allowed in an or-pattern
+    let a : u8 = 0; //~ ERROR a trailing `|` is not allowed in an or-pattern
+    let a = 0; //~ ERROR a trailing `|` is not allowed in an or-pattern
+    let a ; //~ ERROR a trailing `|` is not allowed in an or-pattern
 }
diff --git a/tests/ui/or-patterns/remove-leading-vert.rs b/tests/ui/or-patterns/remove-leading-vert.rs
index 1e1dbfbc6e665..1b4eb669fbb45 100644
--- a/tests/ui/or-patterns/remove-leading-vert.rs
+++ b/tests/ui/or-patterns/remove-leading-vert.rs
@@ -32,7 +32,7 @@ fn trailing() {
     //~^ ERROR a trailing `|` is not allowed in an or-pattern
     match A {
         A | => {} //~ ERROR a trailing `|` is not allowed in an or-pattern
-        A || => {} //~ ERROR a trailing `|` is not allowed in an or-pattern
+        A || => {} //~ ERROR a trailing `||` is not allowed in an or-pattern
         A || B | => {} //~ ERROR unexpected token `||` in pattern
         //~^ ERROR a trailing `|` is not allowed in an or-pattern
         | A | B | => {}
diff --git a/tests/ui/or-patterns/remove-leading-vert.stderr b/tests/ui/or-patterns/remove-leading-vert.stderr
index 0323c64f04231..29450153ba459 100644
--- a/tests/ui/or-patterns/remove-leading-vert.stderr
+++ b/tests/ui/or-patterns/remove-leading-vert.stderr
@@ -3,12 +3,6 @@ error: function parameters require top-level or-patterns in parentheses
    |
 LL |     fn fun1( | A: E) {}
    |              ^^^
-   |
-help: remove the `|`
-   |
-LL -     fn fun1( | A: E) {}
-LL +     fn fun1(  A: E) {}
-   |
 
 error: unexpected `||` before function parameter
   --> $DIR/remove-leading-vert.rs:12:14
@@ -78,12 +72,6 @@ LL |     let ( A | ): E;
    |           - ^
    |           |
    |           while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let ( A | ): E;
-LL +     let ( A  ): E;
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:27:12
@@ -92,12 +80,6 @@ LL |     let (a |,): (E,);
    |          - ^
    |          |
    |          while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let (a |,): (E,);
-LL +     let (a ,): (E,);
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:28:17
@@ -106,12 +88,6 @@ LL |     let ( A | B | ): E;
    |           -     ^
    |           |
    |           while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let ( A | B | ): E;
-LL +     let ( A | B  ): E;
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:29:17
@@ -120,12 +96,6 @@ LL |     let [ A | B | ]: [E; 1];
    |           -     ^
    |           |
    |           while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let [ A | B | ]: [E; 1];
-LL +     let [ A | B  ]: [E; 1];
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:30:18
@@ -134,12 +104,6 @@ LL |     let S { f: B | };
    |                - ^
    |                |
    |                while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let S { f: B | };
-LL +     let S { f: B  };
-   |
 
 error: unexpected token `||` in pattern
   --> $DIR/remove-leading-vert.rs:31:13
@@ -162,12 +126,6 @@ LL |     let ( A || B | ): E;
    |           -      ^
    |           |
    |           while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let ( A || B | ): E;
-LL +     let ( A || B  ): E;
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:34:11
@@ -176,14 +134,8 @@ LL |         A | => {}
    |         - ^
    |         |
    |         while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -         A | => {}
-LL +         A  => {}
-   |
 
-error: a trailing `|` is not allowed in an or-pattern
+error: a trailing `||` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:35:11
    |
 LL |         A || => {}
@@ -192,11 +144,6 @@ LL |         A || => {}
    |         while parsing this or-pattern starting here
    |
    = note: alternatives in or-patterns are separated with `|`, not `||`
-help: remove the `||`
-   |
-LL -         A || => {}
-LL +         A  => {}
-   |
 
 error: unexpected token `||` in pattern
   --> $DIR/remove-leading-vert.rs:36:11
@@ -219,12 +166,6 @@ LL |         A || B | => {}
    |         -      ^
    |         |
    |         while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -         A || B | => {}
-LL +         A || B  => {}
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:38:17
@@ -233,12 +174,6 @@ LL |         | A | B | => {}
    |         -       ^
    |         |
    |         while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -         | A | B | => {}
-LL +         | A | B  => {}
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:45:11
@@ -247,12 +182,6 @@ LL |     let a | : u8 = 0;
    |         - ^
    |         |
    |         while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let a | : u8 = 0;
-LL +     let a  : u8 = 0;
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:46:11
@@ -261,12 +190,6 @@ LL |     let a | = 0;
    |         - ^
    |         |
    |         while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let a | = 0;
-LL +     let a  = 0;
-   |
 
 error: a trailing `|` is not allowed in an or-pattern
   --> $DIR/remove-leading-vert.rs:47:11
@@ -275,12 +198,6 @@ LL |     let a | ;
    |         - ^
    |         |
    |         while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -     let a | ;
-LL +     let a  ;
-   |
 
 error: aborting due to 21 previous errors
 
diff --git a/tests/ui/issues/issue-8391.rs b/tests/ui/pattern/match-with-at-binding-8391.rs
similarity index 73%
rename from tests/ui/issues/issue-8391.rs
rename to tests/ui/pattern/match-with-at-binding-8391.rs
index 20698eed18b7b..bc4e7be798929 100644
--- a/tests/ui/issues/issue-8391.rs
+++ b/tests/ui/pattern/match-with-at-binding-8391.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8391
 //@ run-pass
 
 fn main() {
diff --git a/tests/ui/issues/issue-8860.rs b/tests/ui/pattern/ref-in-function-parameter-patterns-8860.rs
similarity index 94%
rename from tests/ui/issues/issue-8860.rs
rename to tests/ui/pattern/ref-in-function-parameter-patterns-8860.rs
index 3af61576fe1a2..1a67caf021cf7 100644
--- a/tests/ui/issues/issue-8860.rs
+++ b/tests/ui/pattern/ref-in-function-parameter-patterns-8860.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8860
 //@ run-pass
 // FIXME(static_mut_refs): this could use an atomic
 #![allow(static_mut_refs)]
diff --git a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.fixed b/tests/ui/privacy/inaccessible-fields-pattern-matching-76077.fixed
similarity index 90%
rename from tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.fixed
rename to tests/ui/privacy/inaccessible-fields-pattern-matching-76077.fixed
index 6fde4e390fa1a..7d648543a2071 100644
--- a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.fixed
+++ b/tests/ui/privacy/inaccessible-fields-pattern-matching-76077.fixed
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/76077
 //@ run-rustfix
 #![allow(dead_code, unused_variables)]
 
diff --git a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.rs b/tests/ui/privacy/inaccessible-fields-pattern-matching-76077.rs
similarity index 90%
rename from tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.rs
rename to tests/ui/privacy/inaccessible-fields-pattern-matching-76077.rs
index 30a8535faf5cc..f3b51187ae316 100644
--- a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.rs
+++ b/tests/ui/privacy/inaccessible-fields-pattern-matching-76077.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/76077
 //@ run-rustfix
 #![allow(dead_code, unused_variables)]
 
diff --git a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.stderr b/tests/ui/privacy/inaccessible-fields-pattern-matching-76077.stderr
similarity index 83%
rename from tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.stderr
rename to tests/ui/privacy/inaccessible-fields-pattern-matching-76077.stderr
index f54990d5d8618..070fa1a53a547 100644
--- a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077-1.stderr
+++ b/tests/ui/privacy/inaccessible-fields-pattern-matching-76077.stderr
@@ -1,5 +1,5 @@
 error: pattern requires `..` due to inaccessible fields
-  --> $DIR/issue-76077-1.rs:13:9
+  --> $DIR/inaccessible-fields-pattern-matching-76077.rs:14:9
    |
 LL |     let foo::Foo {} = foo::Foo::default();
    |         ^^^^^^^^^^^
@@ -10,7 +10,7 @@ LL |     let foo::Foo { .. } = foo::Foo::default();
    |                    ++
 
 error: pattern requires `..` due to inaccessible fields
-  --> $DIR/issue-76077-1.rs:16:9
+  --> $DIR/inaccessible-fields-pattern-matching-76077.rs:17:9
    |
 LL |     let foo::Bar { visible } = foo::Bar::default();
    |         ^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077.rs b/tests/ui/privacy/private-field-struct-construction-76077.rs
similarity index 80%
rename from tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077.rs
rename to tests/ui/privacy/private-field-struct-construction-76077.rs
index 2d29093b01b02..7fc3473e8decc 100644
--- a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077.rs
+++ b/tests/ui/privacy/private-field-struct-construction-76077.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/76077
 pub mod foo {
     pub struct Foo {
         you_cant_use_this_field: bool,
diff --git a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077.stderr b/tests/ui/privacy/private-field-struct-construction-76077.stderr
similarity index 80%
rename from tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077.stderr
rename to tests/ui/privacy/private-field-struct-construction-76077.stderr
index 3fef5ffce30dc..5131db72fe3bf 100644
--- a/tests/ui/issues/issue-76077-inaccesible-private-fields/issue-76077.stderr
+++ b/tests/ui/privacy/private-field-struct-construction-76077.stderr
@@ -1,5 +1,5 @@
 error: cannot construct `Foo` with struct literal syntax due to private fields
-  --> $DIR/issue-76077.rs:8:5
+  --> $DIR/private-field-struct-construction-76077.rs:9:5
    |
 LL |     foo::Foo {};
    |     ^^^^^^^^
diff --git a/tests/ui/issues/issue-8727.rs b/tests/ui/recursion/infinite-function-recursion-error-8727.rs
similarity index 90%
rename from tests/ui/issues/issue-8727.rs
rename to tests/ui/recursion/infinite-function-recursion-error-8727.rs
index c1b60e8e08509..a4037f761098e 100644
--- a/tests/ui/issues/issue-8727.rs
+++ b/tests/ui/recursion/infinite-function-recursion-error-8727.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8727
 // Verify the compiler fails with an error on infinite function
 // recursions.
 
@@ -9,7 +10,6 @@ fn generic<T>() { //~ WARN function cannot return without recursing
 }
 //~^^ ERROR reached the recursion limit while instantiating `generic::<Option<
 
-
 fn main () {
     // Use generic<T> at least once to trigger instantiation.
     generic::<i32>();
diff --git a/tests/ui/issues/issue-8727.stderr b/tests/ui/recursion/infinite-function-recursion-error-8727.stderr
similarity index 76%
rename from tests/ui/issues/issue-8727.stderr
rename to tests/ui/recursion/infinite-function-recursion-error-8727.stderr
index 9fb09a7d4f42d..13d57ecb3b2f0 100644
--- a/tests/ui/issues/issue-8727.stderr
+++ b/tests/ui/recursion/infinite-function-recursion-error-8727.stderr
@@ -1,5 +1,5 @@
 warning: function cannot return without recursing
-  --> $DIR/issue-8727.rs:7:1
+  --> $DIR/infinite-function-recursion-error-8727.rs:8:1
    |
 LL | fn generic<T>() {
    | ^^^^^^^^^^^^^^^ cannot return without recursing
@@ -10,17 +10,17 @@ LL |     generic::<Option<T>>();
    = note: `#[warn(unconditional_recursion)]` on by default
 
 error: reached the recursion limit while instantiating `generic::<Option<Option<Option<Option<...>>>>>`
-  --> $DIR/issue-8727.rs:8:5
+  --> $DIR/infinite-function-recursion-error-8727.rs:9:5
    |
 LL |     generic::<Option<T>>();
    |     ^^^^^^^^^^^^^^^^^^^^^^
    |
 note: `generic` defined here
-  --> $DIR/issue-8727.rs:7:1
+  --> $DIR/infinite-function-recursion-error-8727.rs:8:1
    |
 LL | fn generic<T>() {
    | ^^^^^^^^^^^^^^^
-   = note: the full name for the type has been written to '$TEST_BUILD_DIR/issue-8727.long-type-$LONG_TYPE_HASH.txt'
+   = note: the full name for the type has been written to '$TEST_BUILD_DIR/infinite-function-recursion-error-8727.long-type-$LONG_TYPE_HASH.txt'
    = note: consider using `--verbose` to print the full type name to the console
 
 error: aborting due to 1 previous error; 1 warning emitted
diff --git a/tests/ui/issues/issue-7663.rs b/tests/ui/resolve/module-import-resolution-7663.rs
similarity index 91%
rename from tests/ui/issues/issue-7663.rs
rename to tests/ui/resolve/module-import-resolution-7663.rs
index d2b2c727cab25..872806594fc40 100644
--- a/tests/ui/issues/issue-7663.rs
+++ b/tests/ui/resolve/module-import-resolution-7663.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/7663
 //@ run-pass
 
 #![allow(unused_imports, dead_code)]
diff --git a/tests/ui/rfcs/rfc-0000-never_patterns/ICE-130779-never-arm-no-oatherwise-block.stderr b/tests/ui/rfcs/rfc-0000-never_patterns/ICE-130779-never-arm-no-oatherwise-block.stderr
index 26731e29ffc57..5f4a5f31e34fb 100644
--- a/tests/ui/rfcs/rfc-0000-never_patterns/ICE-130779-never-arm-no-oatherwise-block.stderr
+++ b/tests/ui/rfcs/rfc-0000-never_patterns/ICE-130779-never-arm-no-oatherwise-block.stderr
@@ -5,12 +5,6 @@ LL |         ! |
    |         - ^
    |         |
    |         while parsing this or-pattern starting here
-   |
-help: remove the `|`
-   |
-LL -         ! |
-LL +         !
-   |
 
 error: a never pattern is always unreachable
   --> $DIR/ICE-130779-never-arm-no-oatherwise-block.rs:10:20
diff --git a/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr b/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr
index 8081f7b3a8b0f..f7750884b4a65 100644
--- a/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr
+++ b/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr
@@ -44,7 +44,7 @@ LL |
 LL |         foo(f);
    |             ^ move occurs because `f` has type `{closure@$DIR/borrowck-call-is-borrow-issue-12224.rs:52:17: 52:58}`, which does not implement the `Copy` trait
    |
-   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
 help: consider cloning the value if the performance cost is acceptable
    |
 LL |         foo(f.clone());
diff --git a/tests/ui/issues/issue-8578.rs b/tests/ui/static/static-struct-with-option-8578.rs
similarity index 90%
rename from tests/ui/issues/issue-8578.rs
rename to tests/ui/static/static-struct-with-option-8578.rs
index 9baa2f70a02db..d490a3f50b419 100644
--- a/tests/ui/issues/issue-8578.rs
+++ b/tests/ui/static/static-struct-with-option-8578.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8578
 //@ check-pass
 #![allow(dead_code)]
 #![allow(non_camel_case_types)]
diff --git a/tests/ui/issues/auxiliary/issue-8044.rs b/tests/ui/structs-enums/auxiliary/aux-8044.rs
similarity index 100%
rename from tests/ui/issues/auxiliary/issue-8044.rs
rename to tests/ui/structs-enums/auxiliary/aux-8044.rs
diff --git a/tests/ui/structs-enums/struct-and-enum-usage-8044.rs b/tests/ui/structs-enums/struct-and-enum-usage-8044.rs
new file mode 100644
index 0000000000000..9b544f33f1c2d
--- /dev/null
+++ b/tests/ui/structs-enums/struct-and-enum-usage-8044.rs
@@ -0,0 +1,10 @@
+// https://github.com/rust-lang/rust/issues/8044
+//@ run-pass
+//@ aux-build:aux-8044.rs
+
+extern crate aux_8044 as minimal;
+use minimal::{BTree, leaf};
+
+pub fn main() {
+    BTree::<isize> { node: leaf(1) };
+}
diff --git a/tests/ui/issues/issue-8783.rs b/tests/ui/structs/destructuring-struct-type-inference-8783.rs
similarity index 88%
rename from tests/ui/issues/issue-8783.rs
rename to tests/ui/structs/destructuring-struct-type-inference-8783.rs
index d0ff79f8ac800..60bc4bf3289e5 100644
--- a/tests/ui/issues/issue-8783.rs
+++ b/tests/ui/structs/destructuring-struct-type-inference-8783.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8783
 //@ run-pass
 #![allow(unused_variables)]
 
diff --git a/tests/ui/suggestions/dont-suggest-ref/move-into-closure.stderr b/tests/ui/suggestions/dont-suggest-ref/move-into-closure.stderr
index 132a31c8f7ceb..39c2fabf9eb14 100644
--- a/tests/ui/suggestions/dont-suggest-ref/move-into-closure.stderr
+++ b/tests/ui/suggestions/dont-suggest-ref/move-into-closure.stderr
@@ -12,7 +12,7 @@ LL |         let X(_t) = x;
    |               data moved here
    |               move occurs because `_t` has type `Y`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -37,7 +37,7 @@ LL |         if let Either::One(_t) = e { }
    |                            data moved here
    |                            move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -62,7 +62,7 @@ LL |         while let Either::One(_t) = e { }
    |                               data moved here
    |                               move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -90,7 +90,7 @@ LL |             Either::One(_t)
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -118,7 +118,7 @@ LL |             Either::One(_t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -143,7 +143,7 @@ LL |         let X(mut _t) = x;
    |               data moved here
    |               move occurs because `_t` has type `Y`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -168,7 +168,7 @@ LL |         if let Either::One(mut _t) = em { }
    |                            data moved here
    |                            move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -193,7 +193,7 @@ LL |         while let Either::One(mut _t) = em { }
    |                               data moved here
    |                               move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -221,7 +221,7 @@ LL |             Either::One(mut _t)
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -249,7 +249,7 @@ LL |             Either::One(mut _t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:13:18
    |
 LL | fn consume_fn<F: Fn()>(_f: F) { }
@@ -273,7 +273,7 @@ LL |         let X(_t) = x;
    |               data moved here
    |               move occurs because `_t` has type `Y`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -298,7 +298,7 @@ LL |         if let Either::One(_t) = e { }
    |                            data moved here
    |                            move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -323,7 +323,7 @@ LL |         while let Either::One(_t) = e { }
    |                               data moved here
    |                               move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -351,7 +351,7 @@ LL |             Either::One(_t)
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -379,7 +379,7 @@ LL |             Either::One(_t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -404,7 +404,7 @@ LL |         let X(mut _t) = x;
    |               data moved here
    |               move occurs because `_t` has type `Y`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -429,7 +429,7 @@ LL |         if let Either::One(mut _t) = em { }
    |                            data moved here
    |                            move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -454,7 +454,7 @@ LL |         while let Either::One(mut _t) = em { }
    |                               data moved here
    |                               move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -482,7 +482,7 @@ LL |             Either::One(mut _t)
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -510,7 +510,7 @@ LL |             Either::One(mut _t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:39:22
    |
 LL |     fn consume_fn<F: Fn()>(_f: F) { }
@@ -534,7 +534,7 @@ LL |         let X(_t) = x;
    |               data moved here
    |               move occurs because `_t` has type `Y`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -559,7 +559,7 @@ LL |         if let Either::One(_t) = e { }
    |                            data moved here
    |                            move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -584,7 +584,7 @@ LL |         while let Either::One(_t) = e { }
    |                               data moved here
    |                               move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -612,7 +612,7 @@ LL |             Either::One(_t)
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -640,7 +640,7 @@ LL |             Either::One(_t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -665,7 +665,7 @@ LL |         let X(mut _t) = x;
    |               data moved here
    |               move occurs because `_t` has type `Y`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -690,7 +690,7 @@ LL |         if let Either::One(mut _t) = em { }
    |                            data moved here
    |                            move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -715,7 +715,7 @@ LL |         while let Either::One(mut _t) = em { }
    |                               data moved here
    |                               move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -743,7 +743,7 @@ LL |             Either::One(mut _t)
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -771,7 +771,7 @@ LL |             Either::One(mut _t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:50:29
    |
 LL |     fn method_consume_fn<F: Fn()>(&self, _f: F) { }
@@ -795,7 +795,7 @@ LL |         let X(_t) = x;
    |               data moved here
    |               move occurs because `_t` has type `Y`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -820,7 +820,7 @@ LL |         if let Either::One(_t) = e { }
    |                            data moved here
    |                            move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -845,7 +845,7 @@ LL |         while let Either::One(_t) = e { }
    |                               data moved here
    |                               move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -873,7 +873,7 @@ LL |             Either::One(_t)
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -901,7 +901,7 @@ LL |             Either::One(_t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -926,7 +926,7 @@ LL |         let X(mut _t) = x;
    |               data moved here
    |               move occurs because `_t` has type `Y`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -951,7 +951,7 @@ LL |         if let Either::One(mut _t) = em { }
    |                            data moved here
    |                            move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -976,7 +976,7 @@ LL |         while let Either::One(mut _t) = em { }
    |                               data moved here
    |                               move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -1004,7 +1004,7 @@ LL |             Either::One(mut _t)
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -1032,7 +1032,7 @@ LL |             Either::One(mut _t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
@@ -1060,7 +1060,7 @@ LL |             Either::One(mut _t) => (),
    |                         data moved here
    |                         move occurs because `_t` has type `X`, which does not implement the `Copy` trait
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/move-into-closure.rs:25:21
    |
 LL | fn consume_fnmut<F: FnMut()>(_f: F) { }
diff --git a/tests/ui/suggestions/option-content-move2.stderr b/tests/ui/suggestions/option-content-move2.stderr
index c8aa6667b583f..5bcbdd711ae77 100644
--- a/tests/ui/suggestions/option-content-move2.stderr
+++ b/tests/ui/suggestions/option-content-move2.stderr
@@ -14,7 +14,7 @@ LL |
 LL |             var = Some(NotCopyable);
    |             --- variable moved due to use in closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/option-content-move2.rs:5:12
    |
 LL | fn func<F: FnMut() -> H, H: FnMut()>(_: F) {}
@@ -44,7 +44,7 @@ LL |
 LL |             var = Some(NotCopyableButCloneable);
    |             --- variable moved due to use in closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/option-content-move2.rs:5:12
    |
 LL | fn func<F: FnMut() -> H, H: FnMut()>(_: F) {}
diff --git a/tests/ui/suggestions/option-content-move3.stderr b/tests/ui/suggestions/option-content-move3.stderr
index 2c9a86c036be4..f78d3cf678629 100644
--- a/tests/ui/suggestions/option-content-move3.stderr
+++ b/tests/ui/suggestions/option-content-move3.stderr
@@ -9,7 +9,7 @@ LL |         move || {
 LL |             let x = var;
    |                     ^^^ move occurs because `var` has type `NotCopyable`, which does not implement the `Copy` trait
    |
-   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
 note: if `NotCopyable` implemented `Clone`, you could clone the value
   --> $DIR/option-content-move3.rs:2:1
    |
@@ -38,7 +38,7 @@ LL |         move || {
 LL |             let x = var;
    |                     --- variable moved due to use in closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/option-content-move3.rs:6:12
    |
 LL | fn func<F: FnMut() -> H, H: FnMut()>(_: F) {}
@@ -63,7 +63,7 @@ LL |         move || {
 LL |             let x = var;
    |                     ^^^ move occurs because `var` has type `NotCopyableButCloneable`, which does not implement the `Copy` trait
    |
-   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+   = help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
 help: consider borrowing here
    |
 LL |             let x = &var;
@@ -84,7 +84,7 @@ LL |         move || {
 LL |             let x = var;
    |                     --- variable moved due to use in closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/option-content-move3.rs:6:12
    |
 LL | fn func<F: FnMut() -> H, H: FnMut()>(_: F) {}
diff --git a/tests/ui/issues/issue-83048.rs b/tests/ui/thir-print/break-outside-loop-error-83048.rs
similarity index 72%
rename from tests/ui/issues/issue-83048.rs
rename to tests/ui/thir-print/break-outside-loop-error-83048.rs
index 6c941133a152c..6dcebd77c27b2 100644
--- a/tests/ui/issues/issue-83048.rs
+++ b/tests/ui/thir-print/break-outside-loop-error-83048.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/83048
 //@ compile-flags: -Z unpretty=thir-tree
 
 pub fn main() {
diff --git a/tests/ui/issues/issue-83048.stderr b/tests/ui/thir-print/break-outside-loop-error-83048.stderr
similarity index 83%
rename from tests/ui/issues/issue-83048.stderr
rename to tests/ui/thir-print/break-outside-loop-error-83048.stderr
index 672bf69a7325b..65a08e62e3df6 100644
--- a/tests/ui/issues/issue-83048.stderr
+++ b/tests/ui/thir-print/break-outside-loop-error-83048.stderr
@@ -1,5 +1,5 @@
 error[E0268]: `break` outside of a loop or labeled block
-  --> $DIR/issue-83048.rs:4:5
+  --> $DIR/break-outside-loop-error-83048.rs:5:5
    |
 LL |     break;
    |     ^^^^^ cannot `break` outside of a loop or labeled block
diff --git a/tests/ui/issues/issue-87707.rs b/tests/ui/track-diagnostics/track-caller-for-once-87707.rs
similarity index 87%
rename from tests/ui/issues/issue-87707.rs
rename to tests/ui/track-diagnostics/track-caller-for-once-87707.rs
index a0da8a740ac39..9b450943f5d7a 100644
--- a/tests/ui/issues/issue-87707.rs
+++ b/tests/ui/track-diagnostics/track-caller-for-once-87707.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/87707
 // test for #87707
 //@ edition:2018
 //@ run-fail
diff --git a/tests/ui/issues/issue-87707.run.stderr b/tests/ui/track-diagnostics/track-caller-for-once-87707.run.stderr
similarity index 50%
rename from tests/ui/issues/issue-87707.run.stderr
rename to tests/ui/track-diagnostics/track-caller-for-once-87707.run.stderr
index 8485c0578b82c..093df62836bfa 100644
--- a/tests/ui/issues/issue-87707.run.stderr
+++ b/tests/ui/track-diagnostics/track-caller-for-once-87707.run.stderr
@@ -1,7 +1,7 @@
 
-thread 'main' ($TID) panicked at $DIR/issue-87707.rs:14:24:
+thread 'main' ($TID) panicked at $DIR/track-caller-for-once-87707.rs:15:24:
 Here Once instance is poisoned.
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 
-thread 'main' ($TID) panicked at $DIR/issue-87707.rs:16:7:
+thread 'main' ($TID) panicked at $DIR/track-caller-for-once-87707.rs:17:7:
 Once instance has previously been poisoned
diff --git a/tests/ui/issues/issue-87199.rs b/tests/ui/trait-bounds/relaxed-bounds-assumed-unsized-87199.rs
similarity index 94%
rename from tests/ui/issues/issue-87199.rs
rename to tests/ui/trait-bounds/relaxed-bounds-assumed-unsized-87199.rs
index dd9dfc74ca352..f3baa4b1feb8d 100644
--- a/tests/ui/issues/issue-87199.rs
+++ b/tests/ui/trait-bounds/relaxed-bounds-assumed-unsized-87199.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/87199
 // Regression test for issue #87199, where attempting to relax a bound
 // other than the only supported `?Sized` would still cause the compiler
 // to assume that the `Sized` bound was relaxed.
diff --git a/tests/ui/issues/issue-87199.stderr b/tests/ui/trait-bounds/relaxed-bounds-assumed-unsized-87199.stderr
similarity index 80%
rename from tests/ui/issues/issue-87199.stderr
rename to tests/ui/trait-bounds/relaxed-bounds-assumed-unsized-87199.stderr
index 8a930a3d704c1..16223676c067e 100644
--- a/tests/ui/issues/issue-87199.stderr
+++ b/tests/ui/trait-bounds/relaxed-bounds-assumed-unsized-87199.stderr
@@ -1,23 +1,23 @@
 error: bound modifier `?` can only be applied to `Sized`
-  --> $DIR/issue-87199.rs:8:11
+  --> $DIR/relaxed-bounds-assumed-unsized-87199.rs:9:11
    |
 LL | fn arg<T: ?Send>(_: T) {}
    |           ^^^^^
 
 error: bound modifier `?` can only be applied to `Sized`
-  --> $DIR/issue-87199.rs:10:15
+  --> $DIR/relaxed-bounds-assumed-unsized-87199.rs:11:15
    |
 LL | fn ref_arg<T: ?Send>(_: &T) {}
    |               ^^^^^
 
 error: bound modifier `?` can only be applied to `Sized`
-  --> $DIR/issue-87199.rs:12:40
+  --> $DIR/relaxed-bounds-assumed-unsized-87199.rs:13:40
    |
 LL | fn ret() -> impl Iterator<Item = ()> + ?Send { std::iter::empty() }
    |                                        ^^^^^
 
 error: bound modifier `?` can only be applied to `Sized`
-  --> $DIR/issue-87199.rs:12:40
+  --> $DIR/relaxed-bounds-assumed-unsized-87199.rs:13:40
    |
 LL | fn ret() -> impl Iterator<Item = ()> + ?Send { std::iter::empty() }
    |                                        ^^^^^
@@ -25,14 +25,14 @@ LL | fn ret() -> impl Iterator<Item = ()> + ?Send { std::iter::empty() }
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: the size for values of type `[i32]` cannot be known at compilation time
-  --> $DIR/issue-87199.rs:19:15
+  --> $DIR/relaxed-bounds-assumed-unsized-87199.rs:20:15
    |
 LL |     ref_arg::<[i32]>(&[5]);
    |               ^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `[i32]`
 note: required by an implicit `Sized` bound in `ref_arg`
-  --> $DIR/issue-87199.rs:10:12
+  --> $DIR/relaxed-bounds-assumed-unsized-87199.rs:11:12
    |
 LL | fn ref_arg<T: ?Send>(_: &T) {}
    |            ^ required by the implicit `Sized` requirement on this type parameter in `ref_arg`
diff --git a/tests/ui/issues/auxiliary/issue-9123.rs b/tests/ui/traits/auxiliary/aux-9123.rs
similarity index 100%
rename from tests/ui/issues/auxiliary/issue-9123.rs
rename to tests/ui/traits/auxiliary/aux-9123.rs
diff --git a/tests/ui/traits/default-method-fn-call-9123.rs b/tests/ui/traits/default-method-fn-call-9123.rs
new file mode 100644
index 0000000000000..266b95ca960c5
--- /dev/null
+++ b/tests/ui/traits/default-method-fn-call-9123.rs
@@ -0,0 +1,7 @@
+// https://github.com/rust-lang/rust/issues/9123
+//@ run-pass
+//@ aux-build:aux-9123.rs
+
+extern crate aux_9123;
+
+pub fn main() {}
diff --git a/tests/ui/issues/issue-8249.rs b/tests/ui/traits/mut-trait-in-struct-8249.rs
similarity index 80%
rename from tests/ui/issues/issue-8249.rs
rename to tests/ui/traits/mut-trait-in-struct-8249.rs
index 2364fc14d31ac..b6dcd848b8b34 100644
--- a/tests/ui/issues/issue-8249.rs
+++ b/tests/ui/traits/mut-trait-in-struct-8249.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8249
 //@ run-pass
 #![allow(dead_code)]
 
diff --git a/tests/ui/issues/issue-7673-cast-generically-implemented-trait.rs b/tests/ui/traits/polymorphic-trait-creation-7673.rs
similarity index 85%
rename from tests/ui/issues/issue-7673-cast-generically-implemented-trait.rs
rename to tests/ui/traits/polymorphic-trait-creation-7673.rs
index edba3284e3175..643818ffe1e52 100644
--- a/tests/ui/issues/issue-7673-cast-generically-implemented-trait.rs
+++ b/tests/ui/traits/polymorphic-trait-creation-7673.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/7673
 //@ check-pass
 #![allow(dead_code)]
 
diff --git a/tests/ui/issues/issue-8171-default-method-self-inherit-builtin-trait.rs b/tests/ui/traits/self-implements-kinds-in-default-methods-8171.rs
similarity index 85%
rename from tests/ui/issues/issue-8171-default-method-self-inherit-builtin-trait.rs
rename to tests/ui/traits/self-implements-kinds-in-default-methods-8171.rs
index 6a03404cdca71..59ea62c7690ee 100644
--- a/tests/ui/issues/issue-8171-default-method-self-inherit-builtin-trait.rs
+++ b/tests/ui/traits/self-implements-kinds-in-default-methods-8171.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8171
 //@ check-pass
 #![allow(dead_code)]
 
diff --git a/tests/ui/issues/issue-7563.rs b/tests/ui/traits/trait-implementation-and-usage-7563.rs
similarity index 91%
rename from tests/ui/issues/issue-7563.rs
rename to tests/ui/traits/trait-implementation-and-usage-7563.rs
index 9ee8857b99960..8cfc7a14ffe66 100644
--- a/tests/ui/issues/issue-7563.rs
+++ b/tests/ui/traits/trait-implementation-and-usage-7563.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/7563
 //@ run-pass
 #![allow(dead_code)]
 trait IDummy {
diff --git a/tests/ui/issues/issue-8767.rs b/tests/ui/typeck/impl-for-nonexistent-type-error-8767.rs
similarity index 59%
rename from tests/ui/issues/issue-8767.rs
rename to tests/ui/typeck/impl-for-nonexistent-type-error-8767.rs
index 972101a0bc3ee..005c676ed39b3 100644
--- a/tests/ui/issues/issue-8767.rs
+++ b/tests/ui/typeck/impl-for-nonexistent-type-error-8767.rs
@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/8767
 impl B { //~ ERROR cannot find type `B` in this scope
 }
 
diff --git a/tests/ui/issues/issue-8767.stderr b/tests/ui/typeck/impl-for-nonexistent-type-error-8767.stderr
similarity index 79%
rename from tests/ui/issues/issue-8767.stderr
rename to tests/ui/typeck/impl-for-nonexistent-type-error-8767.stderr
index 66141628e28d2..0e37391a00f7b 100644
--- a/tests/ui/issues/issue-8767.stderr
+++ b/tests/ui/typeck/impl-for-nonexistent-type-error-8767.stderr
@@ -1,5 +1,5 @@
 error[E0412]: cannot find type `B` in this scope
-  --> $DIR/issue-8767.rs:1:6
+  --> $DIR/impl-for-nonexistent-type-error-8767.rs:2:6
    |
 LL | impl B {
    |      ^ not found in this scope
diff --git a/tests/ui/unboxed-closures/unboxed-closure-illegal-move.stderr b/tests/ui/unboxed-closures/unboxed-closure-illegal-move.stderr
index 9d87402a15bff..266da54941df2 100644
--- a/tests/ui/unboxed-closures/unboxed-closure-illegal-move.stderr
+++ b/tests/ui/unboxed-closures/unboxed-closure-illegal-move.stderr
@@ -10,7 +10,7 @@ LL |         let f = to_fn(|| drop(x));
    |                       |
    |                       captured by this `Fn` closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/unboxed-closure-illegal-move.rs:7:33
    |
 LL | fn to_fn<A:std::marker::Tuple,F:Fn<A>>(f: F) -> F { f }
@@ -32,7 +32,7 @@ LL |         let f = to_fn_mut(|| drop(x));
    |                           |
    |                           captured by this `FnMut` closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/unboxed-closure-illegal-move.rs:8:37
    |
 LL | fn to_fn_mut<A:std::marker::Tuple,F:FnMut<A>>(f: F) -> F { f }
@@ -54,7 +54,7 @@ LL |         let f = to_fn(move || drop(x));
    |                       |
    |                       captured by this `Fn` closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/unboxed-closure-illegal-move.rs:7:33
    |
 LL | fn to_fn<A:std::marker::Tuple,F:Fn<A>>(f: F) -> F { f }
@@ -72,7 +72,7 @@ LL |         let f = to_fn_mut(move || drop(x));
    |                           |
    |                           captured by this `FnMut` closure
    |
-help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
+help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
   --> $DIR/unboxed-closure-illegal-move.rs:8:37
    |
 LL | fn to_fn_mut<A:std::marker::Tuple,F:FnMut<A>>(f: F) -> F { f }