Missing "`no_such_crate` did not match any packages" after `cargo update --breaking`

[anforowicz]

Problem

cargo update -- no_such_crate helpfully reports an error. Unexpectedly such an error is not reported when --breaking (one of -Zunstable-options) is used.

Steps

Repro steps:

$ cargo new foo
$ cd foo
$ cargo build # to generate Cargo.lock
$ cargo update -- no_such_crate
error: package ID specification `no_such_crate` did not match any packages
$ cargo update -Zunstable-options --breaking -- no_such_crate

Expected behavior: both cargo update ... no_such_crate commands should report an error

Actual behavior: only one of the commands reports an error

Possible Solution(s)

No response

Notes

No response

Version

$ cargo version --verbose
cargo 1.92.0-nightly (81c3f77a4 2025-10-10)
release: 1.92.0-nightly
commit-hash: 81c3f77a467359c8be6bc747dc93ec66a6e4ce11
commit-date: 2025-10-10
host: x86_64-unknown-linux-gnu
libgit2: 1.9.1 (sys:0.20.2 vendored)
libcurl: 8.15.0-DEV (sys:0.4.83+curl-8.15.0 vendored ssl:OpenSSL/3.5.4)
ssl: OpenSSL 3.5.4 30 Sep 2025
os: Debian n/a (rodete) [64-bit]

[anforowicz]

When the error is issued, it happens at the following callstack:

   2: <cargo_util_schemas::core::package_id_spec::PackageIdSpec as cargo::core::package_id_spec::PackageIdSpecQuery>::query
             at /usr/local/google/home/lukasza/src/github/cargo/src/cargo/core/package_id_spec.rs:106:13
   3: <cargo_util_schemas::core::package_id_spec::PackageIdSpec as cargo::core::package_id_spec::PackageIdSpecQuery>::query_str
             at /usr/local/google/home/lukasza/src/github/cargo/src/cargo/core/package_id_spec.rs:37:14
   4: cargo::core::resolver::resolve::Resolve::query
             at /usr/local/google/home/lukasza/src/github/cargo/src/cargo/core/resolver/resolve.rs:378:9
   5: cargo::ops::cargo_update::update_lockfile
             at /usr/local/google/home/lukasza/src/github/cargo/src/cargo/ops/cargo_update.rs:106:40
   6: cargo::commands::update::exec
             at /usr/local/google/home/lukasza/src/github/cargo/src/bin/cargo/commands/update.rs:109:9
   7: cargo::cli::Exec::exec
             at /usr/local/google/home/lukasza/src/github/cargo/src/bin/cargo/cli.rs:491:36
   8: cargo::cli::main
             at /usr/local/google/home/lukasza/src/github/cargo/src/bin/cargo/cli.rs:99:14
   9: cargo::main
             at /usr/local/google/home/lukasza/src/github/cargo/src/bin/cargo/main.rs:57:9

With --breaking, cargo::commands::update::exec in src/bin/cargo/commands/update.rs will not call into ops::update_lockfile but instead will call ops::upgrade_manifests which then will iterate over all individual dependencies and then when processing the individual update in fn upgrade_dependency it will just silently skip misspelled/nonexistant crate names - see

cargo/src/cargo/ops/cargo_update.rs

Lines 279 to 293 in cd90026

	if !to_update.is_empty()
	&& !to_update.iter().any(|spec| {
	spec.name() == name.as_str()
	&& dependency.source_id().is_registry()
	&& spec
	.url()
	.map_or(true, |url| url == dependency.source_id().url())
	&& spec
	.version()
	.map_or(true, |v| dependency.version_req().matches(&v))
	})
	{
	trace!("skipping dependency `{name}` not selected for upgrading");
	return Ok(dependency);
	}

I am not sure what this means in terms of potentially trying to add an error detection here. Maybe we want to keep track which to_update specs were "active" and which were ignored (and therefore potentially misspelled and deserving an error)?

[weihanglo]

What does cargo upgrade from cargo-edit do right now?

I feel like that if a spec (to_update) matches nothing, the entire operation should be aborted.

[epage]

Don't remember but I agree that the error handling for this shouldn't change with this flag.

[charmitro]

Gave this a go at #16276