ICE: mgca: `No HirId for DefId`

[matthiaskrgr]

auto-reduced (treereduce-rust):

//@compile-flags: --crate-type=lib
#![feature(min_generic_const_args)]
fn foo<const N: usize, const K: usize>() -> [u32; K] {
    [0; K]
}

original:

//@ ignore-auxiliary (used by `./allow-in-other-module.rs`)

// This should not warn.
#![allow(not_a_real_lint)]

// This should not warn, either.
fn foo<const N: usize, const K: usize>(_data: [u32; N]) -> [u32; K] {
    [0; K]
}

Version information

rustc 1.94.0-nightly (3f4dc1e02 2025-12-14)
binary: rustc
commit-hash: 3f4dc1e02d759aa3c3807d4efc1f7f6e293536a5
commit-date: 2025-12-14
host: x86_64-unknown-linux-gnu
release: 1.94.0-nightly
LLVM version: 21.1.5

Possibly related line of code:

rust/compiler/rustc_middle/src/hir/mod.rs

Lines 378 to 390 in 3f4dc1e

	providers.hir_crate_items = map::hir_crate_items;
	providers.crate_hash = map::crate_hash;
	providers.hir_module_items = map::hir_module_items;
	providers.local_def_id_to_hir_id = |tcx, def_id| match tcx.hir_crate(()).owners[def_id] {
	MaybeOwner::Owner(_) => HirId::make_owner(def_id),
	MaybeOwner::NonOwner(hir_id) => hir_id,
	MaybeOwner::Phantom => bug!("No HirId for {:?}", def_id),
	};
	providers.opt_hir_owner_nodes =
	|tcx, id| tcx.hir_crate(()).owners.get(id)?.as_owner().map(|i| &i.nodes);
	providers.hir_owner_parent = |tcx, owner_id| {
	tcx.opt_local_parent(owner_id.def_id).map_or(CRATE_HIR_ID, |parent_def_id| {
	let parent_owner_id = tcx.local_def_id_to_hir_id(parent_def_id).owner;

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zcrate-attr=feature(min_generic_const_args) --crate-type=lib

Program output

warning: the feature `min_generic_const_args` is incomplete and may not be safe to use and/or cause compiler crashes
 --> <crate attribute>:1:12
  |
1 | #![feature(min_generic_const_args)]
  |            ^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #132980 <https://github.com/rust-lang/rust/issues/132980> for more information
  = note: `#[warn(incomplete_features)]` on by default

warning: function `foo` is never used
 --> /tmp/icemaker_global_tempdir.U3pUa92njTMT/rustc_testrunner_tmpdir_reporting.EHEsm5rsaJxS/mvce.rs:1:4
  |
1 | fn foo<const N: usize, const K: usize>() -> [u32; K] {
  |    ^^^
  |
  = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default

error: internal compiler error: compiler/rustc_middle/src/hir/mod.rs:384:32: No HirId for DefId(0:6 ~ mvce[3999]::foo::{constant#0})


thread 'rustc' (2689906) panicked at compiler/rustc_middle/src/hir/mod.rs:384:32:
Box<dyn Any>
stack backtrace:
   0:     0x7faba2190173 - <<std[e49fa185a119b89b]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[17865207963548b5]::fmt::Display>::fmt
   1:     0x7faba2810648 - core[17865207963548b5]::fmt::write
   2:     0x7faba21a67c6 - <std[e49fa185a119b89b]::sys::stdio::unix::Stderr as std[e49fa185a119b89b]::io::Write>::write_fmt
   3:     0x7faba2166938 - std[e49fa185a119b89b]::panicking::default_hook::{closure#0}
   4:     0x7faba2184043 - std[e49fa185a119b89b]::panicking::default_hook
   5:     0x7faba11741d7 - std[e49fa185a119b89b]::panicking::update_hook::<alloc[756b9f94e2773738]::boxed::Box<rustc_driver_impl[e1c4671be5271ce8]::install_ice_hook::{closure#1}>>::{closure#0}
   6:     0x7faba2184322 - std[e49fa185a119b89b]::panicking::panic_with_hook
   7:     0x7faba11b0c61 - std[e49fa185a119b89b]::panicking::begin_panic::<rustc_errors[c34899de065ee3bb]::ExplicitBug>::{closure#0}
   8:     0x7faba11a12b6 - std[e49fa185a119b89b]::sys::backtrace::__rust_end_short_backtrace::<std[e49fa185a119b89b]::panicking::begin_panic<rustc_errors[c34899de065ee3bb]::ExplicitBug>::{closure#0}, !>
   9:     0x7faba11a0efa - std[e49fa185a119b89b]::panicking::begin_panic::<rustc_errors[c34899de065ee3bb]::ExplicitBug>
  10:     0x7faba11ce351 - <rustc_errors[c34899de065ee3bb]::diagnostic::BugAbort as rustc_errors[c34899de065ee3bb]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  11:     0x7faba1771e09 - rustc_middle[7055997c00c0bb98]::util::bug::opt_span_bug_fmt::<rustc_span[ce53af16555a42ff]::span_encoding::Span>::{closure#0}
  12:     0x7faba1771f92 - rustc_middle[7055997c00c0bb98]::ty::context::tls::with_opt::<rustc_middle[7055997c00c0bb98]::util::bug::opt_span_bug_fmt<rustc_span[ce53af16555a42ff]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  13:     0x7faba176376b - rustc_middle[7055997c00c0bb98]::ty::context::tls::with_context_opt::<rustc_middle[7055997c00c0bb98]::ty::context::tls::with_opt<rustc_middle[7055997c00c0bb98]::util::bug::opt_span_bug_fmt<rustc_span[ce53af16555a42ff]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  14:     0x7fab9fc6b994 - rustc_middle[7055997c00c0bb98]::util::bug::bug_fmt
  15:     0x7faba28f3a47 - rustc_query_impl[462c6a5584cea8d4]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[462c6a5584cea8d4]::query_impl::local_def_id_to_hir_id::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7055997c00c0bb98]::query::erase::Erased<[u8; 8usize]>>
  16:     0x7faba28f2e37 - rustc_query_system[5be0c069f6d5c539]::query::plumbing::try_execute_query::<rustc_query_impl[462c6a5584cea8d4]::DynamicConfig<rustc_data_structures[30161969bbcb553f]::vec_cache::VecCache<rustc_span[ce53af16555a42ff]::def_id::LocalDefId, rustc_middle[7055997c00c0bb98]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[5be0c069f6d5c539]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[462c6a5584cea8d4]::plumbing::QueryCtxt, false>
  17:     0x7faba28f2b8b - rustc_query_impl[462c6a5584cea8d4]::query_impl::local_def_id_to_hir_id::get_query_non_incr::__rust_end_short_backtrace
  18:     0x7faba323692e - <rustc_metadata[2002d9e21ce78884]::rmeta::encoder::EncodeContext>::encode_def_ids
  19:     0x7faba324f4df - <rustc_metadata[2002d9e21ce78884]::rmeta::encoder::EncodeContext>::encode_crate_root
  20:     0x7faba3c2b32a - <rustc_metadata[2002d9e21ce78884]::rmeta::encoder::encode_metadata::{closure#3} as core[17865207963548b5]::ops::function::FnOnce<(rustc_middle[7055997c00c0bb98]::ty::context::TyCtxt, &std[e49fa185a119b89b]::path::Path)>>::call_once
  21:     0x7faba3c28553 - rustc_metadata[2002d9e21ce78884]::rmeta::encoder::encode_metadata
  22:     0x7faba3923781 - rustc_metadata[2002d9e21ce78884]::fs::encode_and_write_metadata
  23:     0x7faba3b30125 - <rustc_interface[50af632e35c6bce3]::queries::Linker>::codegen_and_build_linker
  24:     0x7faba3b2ce9c - <rustc_interface[50af632e35c6bce3]::passes::create_and_enter_global_ctxt<core[17865207963548b5]::option::Option<rustc_interface[50af632e35c6bce3]::queries::Linker>, rustc_driver_impl[e1c4671be5271ce8]::run_compiler::{closure#0}::{closure#2}>::{closure#2} as core[17865207963548b5]::ops::function::FnOnce<(&rustc_session[307f8e7a4263bd4]::session::Session, rustc_middle[7055997c00c0bb98]::ty::context::CurrentGcx, alloc[756b9f94e2773738]::sync::Arc<rustc_data_structures[30161969bbcb553f]::jobserver::Proxy>, &std[e49fa185a119b89b]::sync::once_lock::OnceLock<rustc_middle[7055997c00c0bb98]::ty::context::GlobalCtxt>, &rustc_data_structures[30161969bbcb553f]::sync::worker_local::WorkerLocal<rustc_middle[7055997c00c0bb98]::arena::Arena>, &rustc_data_structures[30161969bbcb553f]::sync::worker_local::WorkerLocal<rustc_hir[5d00f225b65c0257]::Arena>, rustc_driver_impl[e1c4671be5271ce8]::run_compiler::{closure#0}::{closure#2})>>::call_once::{shim:vtable#0}
  25:     0x7faba39c19da - rustc_interface[50af632e35c6bce3]::interface::run_compiler::<(), rustc_driver_impl[e1c4671be5271ce8]::run_compiler::{closure#0}>::{closure#1}
  26:     0x7faba3931d8e - std[e49fa185a119b89b]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[50af632e35c6bce3]::util::run_in_thread_with_globals<rustc_interface[50af632e35c6bce3]::util::run_in_thread_pool_with_globals<rustc_interface[50af632e35c6bce3]::interface::run_compiler<(), rustc_driver_impl[e1c4671be5271ce8]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  27:     0x7faba3931b60 - <std[e49fa185a119b89b]::thread::lifecycle::spawn_unchecked<rustc_interface[50af632e35c6bce3]::util::run_in_thread_with_globals<rustc_interface[50af632e35c6bce3]::util::run_in_thread_pool_with_globals<rustc_interface[50af632e35c6bce3]::interface::run_compiler<(), rustc_driver_impl[e1c4671be5271ce8]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[17865207963548b5]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  28:     0x7faba39374f8 - <std[e49fa185a119b89b]::sys::thread::unix::Thread>::new::thread_start
  29:     0x7fab9d2969cb - <unknown>
  30:     0x7fab9d31aa0c - <unknown>
  31:                0x0 - <unknown>

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: please make sure that you have updated to the latest nightly

note: rustc 1.94.0-nightly (3f4dc1e02 2025-12-14) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z crate-attr=feature(min_generic_const_args) --crate-type lib -Z dump-mir-dir=dir

query stack during panic:
#0 [local_def_id_to_hir_id] getting HIR ID of `foo::{constant#0}`
end of query stack
error: aborting due to 1 previous error; 2 warnings emitted

@rustbot label +F-min_generic_const_args

since dc47a69

[matthiaskrgr]

//@compile-flags: --crate-type lib
#![feature(min_generic_const_args)]
fn foo<const K : usize>() -> [u32; K] { [0; K] }
fn main() {}