feat(test): Make CARGO_BIN_EXE_ available at runtime by epage · Pull Request #16421 · rust-lang/cargo

epage · 2025-12-19T21:16:21Z

This also makes artifact deps available for consistency purposes.

What does this PR try to resolve?

I originally proposed this for when moving Cargo off of Cargo's own
internals but went with a different solution.

Re-visiting this because assert_cmd has 2300+ dependents and it seems
like making assert_cmd::cargo_bin work would be a better use of time
than migrating all of those users to assert_cmd::cargo_bin!.
For example, within the top 130 dependents (100,000 downloads or more),
I found 66 that used assert_cmd::cargo_bin
(rust-lang/rust#149852).

The reason to make CARGO_BIN_EXE set only at build-time was to
address the concern of manually running the test executable.
It's not
too common for tests to look at any runtime environment variables
(that I know of), so it usually just works (like running
gdb target/debug/.../test-xxx).
The concern was that if it were set at
runtime it would move more down the path where directly running the test
executable doesn't "just work".

See https://rust-lang.zulipchat.com/#narrow/channel/246057-t-cargo/topic/cargo_bin_exe.20and.20tests/near/513638220

However,

This is user opt-in
Users can run with -vv to see the env variables that are set
Users can run CARGO_TARGET_..._RUNNER=gdb
We can notify the cargo nextest, the main third-party test runner,
about this. It should be easy to support as they have their own
version of this, see https://nexte.st/docs/configuration/env-vars/?h=nextest_bin_exe#environment-variables-nextest-sets

How to test and review this PR?

The CARGO_BIN_EXE_ code now also runs during

cargo rustdoc --test <name>
build scripts
doctests

For build scripts and doctests, the unit filter means that nothing has changed.

For cargo rustdoc --test <name>, this technically fixes a bug where running that on a test that calls env!("CARGO_BIN_EXE_foo") would fail. However, --test is broken more generally and we've talked about removing it (#13427) so I didn't add tests to cover this.

Seeing as this is an implicit artifact At this new location, it will now run as part of `cargo rustdoc --test <name>` which technically fixes a bug but `--test` is not really supported (rust-lang#13427) so I didn't mark this as a `fix` nor did I add tests.

This now runs in build scripts and doctests *but* the unit check should prevent any side effects from happening.

This also makes artifact deps available for consistency purposes. I originally proposed this for when moving Cargo off of Cargo's own internals but went with a different solution. Re-visiting this because `assert_cmd` has 2300+ dependents and it seems like making `assert_cmd::cargo_bin` work would be a better use of time than migrating all of those users to `assert_cmd::cargo_bin!`. For example, within the top 130 dependents (100,000 downloads or more), I found 66 that used `assert_cmd::cargo_bin` (rust-lang/rust#149852). > The reason to make `CARGO_BIN_EXE` set only at build-time was to > address the concern of manually running the test executable. > It's not > too common for tests to look at any runtime environment variables > (that I know of), so it usually just works (like running > `gdb target/debug/.../test-xxx`). > The concern was that if it were set at > runtime it would move more down the path where directly running the test > executable doesn't "just work". See https://rust-lang.zulipchat.com/#narrow/channel/246057-t-cargo/topic/cargo_bin_exe.20and.20tests/near/513638220 However, - This is user opt-in - Users can run with `-vv` to see the env variables that are set - Users can run `CARGO_TARGET_..._RUNNER=gdb` - We can notify the `cargo nextest`, the main third-party test runner, about this. It should be easy to support as they have their own version of this, see https://nexte.st/docs/configuration/env-vars/?h=nextest_bin_exe#environment-variables-nextest-sets

rustbot · 2025-12-19T21:16:25Z

r? @ehuss

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They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

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epage · 2025-12-19T21:16:33Z

src/cargo/core/compiler/artifact.rs

This will need an FCP

I was a bit confused. The "Make CARGO_BIN_EXE_ available at runtime" itself needs FCP, not this specific refactor commit, right?

epage · 2025-12-26T19:59:29Z

CC @sunshowers

sunshowers · 2025-12-26T21:42:32Z

Thanks, excited about this. One thing I'd note is that many environments such as shells silently drop environment variables which have hyphens in them -- for those environments (e.g. under Cargo target runners or nextest wrapper scripts), I make a version of these variables available that replaces hyphens with underscores. Would recommend both variables also be made available in Cargo.

epage · 2025-12-26T21:46:35Z

Thanks for noting that. That seems orthogonal to this and would be good for an issue to be opened to discuss and track that.

sunshowers · 2025-12-26T21:55:06Z

Thanks for noting that. That seems orthogonal to this and would be good for an issue to be opened to discuss and track that.

#16438

weihanglo

This looks great! Thanks for the fix.

View changes since this review

weihanglo · 2025-12-27T00:23:33Z

Users can run with -vv to see the env variables that are set

Unrelated but this reminds me that we might also want to print the working directory in verbose mode (or -vvv) for prosperity reason.

rust-rfcbot · 2026-01-06T15:19:28Z

🔔 This is now entering its final comment period, as per the review above. 🔔

rustbot · 2026-01-07T18:15:48Z

This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

weihanglo

As this is more an addition and less controversial, merge it now so we can get feedback sooner before beta branch off.

View changes since this review

Update cargo submodule 24 commits in 94c368ad2b9db0f0da5bdd8421cea13786ce4412..fc4c92b64d1e0046b66cbdc747cc1c17af8b35a0 2025-12-26 19:39:15 +0000 to 2026-01-08 06:54:56 +0000 - Fixed incorrect version comparision during build script dependency selection (rust-lang/cargo#16486) - refactor: new type for unit index (rust-lang/cargo#16485) - feat(test): Make CARGO_BIN_EXE_ available at runtime (rust-lang/cargo#16421) - fix(package): detect dirty files when run from workspace member (rust-lang/cargo#16479) - fix(timing)!: remove `--timings=<FMT>` optional format values (rust-lang/cargo#16420) - docs(unstable): expand docs for `-Zbuild-analysis` (rust-lang/cargo#16476) - test: add `-Zunstable-options` with custom targets (rust-lang/cargo#16467) - feat(report): add cargo report rebuilds (rust-lang/cargo#16456) - feat(test-support): Use test name for dir when running tests (rust-lang/cargo#16121) - refactor: Migrate some cases to expect/reason (rust-lang/cargo#16461) - docs(build-script): clarify OUT_DIR is not cleaned between builds (rust-lang/cargo#16437) - chore: Update dependencies (rust-lang/cargo#16460) - Update handlebars to 6.4.0 (rust-lang/cargo#16457) - chore(deps): update alpine docker tag to v3.23 (rust-lang/cargo#16454) - Any build scripts can now use cargo::metadata=KEY=VALUE (rust-lang/cargo#16436) - fix(log): add `dependencies` field to `UnitRegistered` (rust-lang/cargo#16448) - Implement fine grain locking for `build-dir` (rust-lang/cargo#16155) - feat(resolver): List features when no close match (rust-lang/cargo#16445) - feat(report): new command `cargo report sessions` (rust-lang/cargo#16428) - feat (patch): Display where the patch was defined in patch-related error messages (rust-lang/cargo#16407) - test(build-rs): Reduce from 'build' to 'check' where possible (rust-lang/cargo#16444) - feat(toml): TOML 1.1 parse support (rust-lang/cargo#16415) - feat(report): support --manifest-path in `cargo report timings` (rust-lang/cargo#16441) - fix(vendor): recursively filter git files in subdirectories (rust-lang/cargo#16439)

Update cargo submodule 27 commits in 94c368ad2b9db0f0da5bdd8421cea13786ce4412..8c133afcd5e0d69932fe11f5907683723f8d361d 2025-12-26 19:39:15 +0000 to 2026-01-09 03:50:15 +0000 - Isolate build script metadata progation between std and non-std crates (rust-lang/cargo#16489) - Add Clippy like lint groups (rust-lang/cargo#16464) - feat: in-memory only `Manifest` (rust-lang/cargo#16409) - Fixed incorrect version comparision during build script dependency selection (rust-lang/cargo#16486) - refactor: new type for unit index (rust-lang/cargo#16485) - feat(test): Make CARGO_BIN_EXE_ available at runtime (rust-lang/cargo#16421) - fix(package): detect dirty files when run from workspace member (rust-lang/cargo#16479) - fix(timing)!: remove `--timings=<FMT>` optional format values (rust-lang/cargo#16420) - docs(unstable): expand docs for `-Zbuild-analysis` (rust-lang/cargo#16476) - test: add `-Zunstable-options` with custom targets (rust-lang/cargo#16467) - feat(report): add cargo report rebuilds (rust-lang/cargo#16456) - feat(test-support): Use test name for dir when running tests (rust-lang/cargo#16121) - refactor: Migrate some cases to expect/reason (rust-lang/cargo#16461) - docs(build-script): clarify OUT_DIR is not cleaned between builds (rust-lang/cargo#16437) - chore: Update dependencies (rust-lang/cargo#16460) - Update handlebars to 6.4.0 (rust-lang/cargo#16457) - chore(deps): update alpine docker tag to v3.23 (rust-lang/cargo#16454) - Any build scripts can now use cargo::metadata=KEY=VALUE (rust-lang/cargo#16436) - fix(log): add `dependencies` field to `UnitRegistered` (rust-lang/cargo#16448) - Implement fine grain locking for `build-dir` (rust-lang/cargo#16155) - feat(resolver): List features when no close match (rust-lang/cargo#16445) - feat(report): new command `cargo report sessions` (rust-lang/cargo#16428) - feat (patch): Display where the patch was defined in patch-related error messages (rust-lang/cargo#16407) - test(build-rs): Reduce from 'build' to 'check' where possible (rust-lang/cargo#16444) - feat(toml): TOML 1.1 parse support (rust-lang/cargo#16415) - feat(report): support --manifest-path in `cargo report timings` (rust-lang/cargo#16441) - fix(vendor): recursively filter git files in subdirectories (rust-lang/cargo#16439)

Pkgsrc changes: * Update version & checksums. * Adapt patches to new vendored crates. This has so far just been verified to build on NetBSD/amd64. Upstream changes relative to 1.93.1: Version 1.94.0 (2026-03-05) ========================== Language -------- - [Impls and impl items inherit `dead_code` lint level of the corresponding traits and trait items] (rust-lang/rust#144113) - [Stabilize additional 29 RISC-V target features including large portions of the RVA22U64 / RVA23U64 profiles] (rust-lang/rust#145948) - [Add warn-by-default `unused_visibilities` lint for visibility on `const _` declarations] (rust-lang/rust#147136) - [Update to Unicode 17] (rust-lang/rust#148321) - [Avoid incorrect lifetime errors for closures] (rust-lang/rust#148329) Platform Support ---------------- - [Add `riscv64im-unknown-none-elf` as a tier 3 target] (rust-lang/rust#148790) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. [platform-support-doc]: https://doc.rust-lang.org/rustc/platform-support.html Libraries --------- - [Relax `T: Ord` bound for some `BinaryHeap<T>` methods.] (rust-lang/rust#149408) Stabilized APIs --------------- - [`<[T]>::array_windows`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.array_windows) - [`<[T]>::element_offset`] (https://doc.rust-lang.org/stable/std/primitive.slice.html#method.element_offset) - [`LazyCell::get`] (https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.get) - [`LazyCell::get_mut`] (https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.get_mut) - [`LazyCell::force_mut`] (https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.force_mut) - [`LazyLock::get`] (https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.get) - [`LazyLock::get_mut`] (https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.get_mut) - [`LazyLock::force_mut`] (https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.force_mut) - [`impl TryFrom<char> for usize`] (https://doc.rust-lang.org/stable/std/convert/trait.TryFrom.html#impl-TryFrom%3Cchar%3E-for-usize) - [`std::iter::Peekable::next_if_map`] (https://doc.rust-lang.org/stable/std/iter/struct.Peekable.html#method.next_if_map) - [`std::iter::Peekable::next_if_map_mut`] (https://doc.rust-lang.org/stable/std/iter/struct.Peekable.html#method.next_if_map_mut) - [x86 `avx512fp16` intrinsics] (rust-lang/rust#127213) (excluding those that depend directly on the unstable `f16` type) - [AArch64 NEON fp16 intrinsics] (rust-lang/rust#136306) (excluding those that depend directly on the unstable `f16` type) - [`f32::consts::EULER_GAMMA`] (https://doc.rust-lang.org/stable/std/f32/consts/constant.EULER_GAMMA.html) - [`f64::consts::EULER_GAMMA`] (https://doc.rust-lang.org/stable/std/f64/consts/constant.EULER_GAMMA.html) - [`f32::consts::GOLDEN_RATIO`] (https://doc.rust-lang.org/stable/std/f32/consts/constant.GOLDEN_RATIO.html) - [`f64::consts::GOLDEN_RATIO`] (https://doc.rust-lang.org/stable/std/f64/consts/constant.GOLDEN_RATIO.html) These previously stable APIs are now stable in const contexts: - [`f32::mul_add`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.mul_add) - [`f64::mul_add`] (https://doc.rust-lang.org/stable/std/primitive.f64.html#method.mul_add) Cargo ----- - Stabilize the config include key. The top-level include config key allows loading additional config files, enabling better organization, sharing, and management of Cargo configurations across projects and environments. [docs] (https://doc.rust-lang.org/nightly/cargo/reference/config.html#including-extra-configuration-files) [#16284] (rust-lang/cargo#16284) - Stabilize the pubtime field in registry index. This records when a crate version was published and enables time-based dependency resolution in the future. Note that crates.io will gradually backfill existing packages when a new version is published. Not all crates have pubtime yet. [#16369] (rust-lang/cargo#16369) [#16372] (rust-lang/cargo#16372) - Cargo now parses [TOML v1.1](https://toml.io/en/v1.1.0) for manifests and configuration files. Note that using these features in Cargo.toml will raise your development MSRV, but the published manifest remains compatible with older parsers. [#16415] (rust-lang/cargo#16415) - [Make `CARGO_BIN_EXE_<crate>` available at runtime ] (rust-lang/cargo#16421) Compatibility Notes ------------------- - [Forbid freely casting lifetime bounds of `dyn`-types] (rust-lang/rust#136776) - [Make closure capturing have consistent and correct behaviour around patterns] (rust-lang/rust#138961) Some finer details of how precise closure captures get affected by pattern matching have been changed. In some cases, this can cause a non-move closure that was previously capturing an entire variable by move, to now capture only part of that variable by move, and other parts by borrow. This can cause the borrow checker to complain where it previously didn't, or cause `Drop` to run at a different point in time. - [Standard library macros are now imported via prelude, not via injected ` #[macro_use]`] (rust-lang/rust#139493) This will raise an error if macros of the same name are glob imported. For example if a crate defines their own `matches` macro and then glob imports that, it's now ambiguous whether the custom or standard library `matches` is meant and an explicit import of the name is required to resolve the ambiguity. One exception is `core::panic` and `std::panic`, if their import is ambiguous a new warning ([`ambiguous_panic_imports`] (rust-lang/rust#147319)) is raised. This may raise a new warning ([`ambiguous_panic_imports`] (rust-lang/rust#147319)) on `#![no_std]` code glob importing the std crate. Both `core::panic!` and `std::panic!` are then in scope and which is used is ambiguous. - [Don't strip shebang in expression-context `include!(…)`s] (rust-lang/rust#146377) This can cause previously working includes to no longer compile if they included files which started with a shebang. - [Ambiguous glob reexports are now also visible cross-crate] (rust-lang/rust#147984) This unifies behavior between local and cross-crate errors on these exports, which may introduce new ambiguity errors. - [Don't normalize where-clauses before checking well-formedness] (rust-lang/rust#148477) - [Introduce a future compatibility warning on codegen attributes on body-free trait methods] (rust-lang/rust#148756) These attributes currently have no effect in this position. - [On Windows `std::time::SystemTime::checked_sub_duration` will return `None` for times before the Windows epoch (1/1/1601)] (rust-lang/rust#148825) - [Lifetime identifiers such as `'a` are now NFC normalized] (rust-lang/rust#149192). - [Overhaul filename handling for cross-compiler consistency] (rust-lang/rust#149709) Any paths emitted by compiler now always respect the relative-ness of the paths and `--remap-path-prefix` given originally. One side-effect of this change is that paths emitted for local crates in Cargo (path dependencies and workspace members) are no longer absolute but relative when emitted as part of a diagnostic in a downstream crate. Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Switch to `annotate-snippets` for error emission] (rust-lang/rust#150032) This should preserve mostly the same outputs in rustc error messages.

This MR contains the following updates: | Package | Update | Change | |---|---|---| | [rust](https://github.com/rust-lang/rust) | minor | `1.93.1` → `1.94.0` | MR created with the help of [el-capitano/tools/renovate-bot](https://gitlab.com/el-capitano/tools/renovate-bot). **Proposed changes to behavior should be submitted there as MRs.** --- ### Release Notes <details> <summary>rust-lang/rust (rust)</summary> ### [`v1.94.0`](https://github.com/rust-lang/rust/blob/HEAD/RELEASES.md#Version-1940-2026-03-05) [Compare Source](rust-lang/rust@1.93.1...1.94.0) \========================== <a id="1.94.0-Language"></a> ## Language - [Impls and impl items inherit `dead_code` lint level of the corresponding traits and trait items](rust-lang/rust#144113) - [Stabilize additional 29 RISC-V target features including large portions of the RVA22U64 / RVA23U64 profiles](rust-lang/rust#145948) - [Add warn-by-default `unused_visibilities` lint for visibility on `const _` declarations](rust-lang/rust#147136) - [Update to Unicode 17](rust-lang/rust#148321) - [Avoid incorrect lifetime errors for closures](rust-lang/rust#148329) <a id="1.94.0-Platform-Support"></a> ## Platform Support - [Add `riscv64im-unknown-none-elf` as a tier 3 target](rust-lang/rust#148790) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. [platform-support-doc]: https://doc.rust-lang.org/rustc/platform-support.html <a id="1.94.0-Libraries"></a> ## Libraries - [Relax `T: Ord` bound for some `BinaryHeap<T>` methods.](rust-lang/rust#149408) <a id="1.94.0-Stabilized-APIs"></a> ## Stabilized APIs - [`<[T]>::array_windows`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.array_windows) - [`<[T]>::element_offset`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.element_offset) - [`LazyCell::get`](https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.get) - [`LazyCell::get_mut`](https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.get_mut) - [`LazyCell::force_mut`](https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.force_mut) - [`LazyLock::get`](https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.get) - [`LazyLock::get_mut`](https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.get_mut) - [`LazyLock::force_mut`](https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.force_mut) - [`impl TryFrom<char> for usize`](https://doc.rust-lang.org/stable/std/convert/trait.TryFrom.html#impl-TryFrom%3Cchar%3E-for-usize) - [`std::iter::Peekable::next_if_map`](https://doc.rust-lang.org/stable/std/iter/struct.Peekable.html#method.next_if_map) - [`std::iter::Peekable::next_if_map_mut`](https://doc.rust-lang.org/stable/std/iter/struct.Peekable.html#method.next_if_map_mut) - [x86 `avx512fp16` intrinsics](rust-lang/rust#127213) (excluding those that depend directly on the unstable `f16` type) - [AArch64 NEON fp16 intrinsics](rust-lang/rust#136306) (excluding those that depend directly on the unstable `f16` type) - [`f32::consts::EULER_GAMMA`](https://doc.rust-lang.org/stable/std/f32/consts/constant.EULER_GAMMA.html) - [`f64::consts::EULER_GAMMA`](https://doc.rust-lang.org/stable/std/f64/consts/constant.EULER_GAMMA.html) - [`f32::consts::GOLDEN_RATIO`](https://doc.rust-lang.org/stable/std/f32/consts/constant.GOLDEN_RATIO.html) - [`f64::consts::GOLDEN_RATIO`](https://doc.rust-lang.org/stable/std/f64/consts/constant.GOLDEN_RATIO.html) These previously stable APIs are now stable in const contexts: - [`f32::mul_add`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.mul_add) - [`f64::mul_add`](https://doc.rust-lang.org/stable/std/primitive.f64.html#method.mul_add) <a id="1.94.0-Cargo"></a> ## Cargo - Stabilize the config include key. The top-level include config key allows loading additional config files, enabling better organization, sharing, and management of Cargo configurations across projects and environments. [docs](https://doc.rust-lang.org/nightly/cargo/reference/config.html#including-extra-configuration-files) [#16284](rust-lang/cargo#16284) - Stabilize the pubtime field in registry index. This records when a crate version was published and enables time-based dependency resolution in the future. Note that crates.io will gradually backfill existing packages when a new version is published. Not all crates have pubtime yet. [#16369](rust-lang/cargo#16369) [#16372](rust-lang/cargo#16372) - Cargo now parses [TOML v1.1](https://toml.io/en/v1.1.0) for manifests and configuration files. Note that using these features in Cargo.toml will raise your development MSRV, but the published manifest remains compatible with older parsers. [#16415](rust-lang/cargo#16415) - [Make `CARGO_BIN_EXE_<crate>` available at runtime ](rust-lang/cargo#16421) <a id="1.94.0-Compatibility-Notes"></a> ## Compatibility Notes - [Forbid freely casting lifetime bounds of `dyn`-types](rust-lang/rust#136776) - [Make closure capturing have consistent and correct behaviour around patterns](rust-lang/rust#138961) Some finer details of how precise closure captures get affected by pattern matching have been changed. In some cases, this can cause a non-move closure that was previously capturing an entire variable by move, to now capture only part of that variable by move, and other parts by borrow. This can cause the borrow checker to complain where it previously didn't, or cause `Drop` to run at a different point in time. - [Standard library macros are now imported via prelude, not via injected `#[macro_use]`](rust-lang/rust#139493) This will raise an error if macros of the same name are glob imported. For example if a crate defines their own `matches` macro and then glob imports that, it's now ambiguous whether the custom or standard library `matches` is meant and an explicit import of the name is required to resolve the ambiguity. One exception is `core::panic` and `std::panic`, if their import is ambiguous a new warning ([`ambiguous_panic_imports`](rust-lang/rust#147319)) is raised. This may raise a new warning ([`ambiguous_panic_imports`](rust-lang/rust#147319)) on `#![no_std]` code glob importing the std crate. Both `core::panic!` and `std::panic!` are then in scope and which is used is ambiguous. - [Don't strip shebang in expression-context `include!(…)`s](rust-lang/rust#146377) This can cause previously working includes to no longer compile if they included files which started with a shebang. - [Ambiguous glob reexports are now also visible cross-crate](rust-lang/rust#147984) This unifies behavior between local and cross-crate errors on these exports, which may introduce new ambiguity errors. - [Don't normalize where-clauses before checking well-formedness](rust-lang/rust#148477) - [Introduce a future compatibility warning on codegen attributes on body-free trait methods](rust-lang/rust#148756) These attributes currently have no effect in this position. - [On Windows `std::time::SystemTime::checked_sub_duration` will return `None` for times before the Windows epoch (1/1/1601)](rust-lang/rust#148825) - [Lifetime identifiers such as `'a` are now NFC normalized](rust-lang/rust#149192). - [Overhaul filename handling for cross-compiler consistency](rust-lang/rust#149709) Any paths emitted by compiler now always respect the relative-ness of the paths and `--remap-path-prefix` given originally. One side-effect of this change is that paths emitted for local crates in Cargo (path dependencies and workspace members) are no longer absolute but relative when emitted as part of a diagnostic in a downstream crate. <a id="1.94.0-Internal-Changes"></a> ## Internal Changes These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Switch to `annotate-snippets` for error emission](rust-lang/rust#150032) This should preserve mostly the same outputs in rustc error messages. </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this MR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this MR, check this box --- This MR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).

epage added 7 commits December 19, 2025 13:43

refactor(compile): Only generate the name if needed

6ff0287

refactor(compile): Use the binary name for the placeholder

c574ad3

refactor(compile): Move implicit artfacts into explicit artifacts

6e0bb91

This now runs in build scripts and doctests *but* the unit check should prevent any side effects from happening.

refactor(compile): Relax traits for UnitOutput

13e120b

test(test): Show runtime behavior of CARGO_BIN_EXE

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epage added the T-cargo Team: Cargo label Dec 19, 2025

rustbot assigned ehuss Dec 19, 2025

rustbot added A-build-execution Area: anything dealing with executing the compiler A-build-scripts Area: build.rs scripts Command-run Command-test S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Dec 19, 2025

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Crater run for cargo build-dir changes rust-lang/rust#149852

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epage force-pushed the test branch from 76ea0eb to 94156a9 Compare December 19, 2025 22:31

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epage force-pushed the test branch from 94156a9 to 8e0bbbc Compare December 26, 2025 19:58

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sunshowers mentioned this pull request Dec 26, 2025

Make CARGO_BIN_EXE_ available with underscores substituted for hyphens #16438

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weihanglo approved these changes Dec 27, 2025

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epage force-pushed the test branch from 8e0bbbc to a94e983 Compare December 29, 2025 13:55

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ehuss moved this to FCP merge in Cargo status tracker Jan 6, 2026

ehuss added this to Cargo status tracker Jan 6, 2026

rust-rfcbot added final-comment-period FCP — a period for last comments before action is taken and removed proposed-final-comment-period An FCP proposal has started, but not yet signed off. labels Jan 6, 2026

epage force-pushed the test branch from 3b6bedf to fb81b05 Compare January 7, 2026 18:15

weihanglo approved these changes Jan 7, 2026

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weihanglo added this pull request to the merge queue Jan 7, 2026

Merged via the queue into rust-lang:master with commit 29154a6 Jan 7, 2026
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rustbot removed the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jan 7, 2026

weihanglo mentioned this pull request Jan 8, 2026

Update cargo submodule rust-lang/rust#150739

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epage deleted the test branch January 9, 2026 17:12

rustbot added this to the 1.94.0 milestone Jan 9, 2026

rust-rfcbot added finished-final-comment-period FCP complete to-announce and removed final-comment-period FCP — a period for last comments before action is taken labels Jan 16, 2026

Mark-Simulacrum mentioned this pull request Jan 25, 2026

Draft release notes for 1.94.0 rust-lang/rust#151650

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epage mentioned this pull request Mar 11, 2026

Relies on internals of Cargo and will break with existing / upcoming features slowli/term-transcript#269

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