Gate #![reexport_test_harness_main] properly by Ozzy1423 · Pull Request #152210 · rust-lang/rust

Ozzy1423 · 2026-02-06T07:24:29Z

Address the FIXME

Removed from issue-43106-gating-of-builtin-attrs.rs since that is for stable attributes only.

This would be a breaking change, search of github shows it is mostly but not always used with #![test_runner] which is already gated correctly.

Details:
#50297

Feel free to close this issue if you think it is not worth addressing the FIXME...

rustbot · 2026-02-06T07:24:33Z

rust-analyzer is developed in its own repository. If possible, consider making this change to rust-lang/rust-analyzer instead.

cc @rust-lang/rust-analyzer

rustbot · 2026-02-06T07:24:35Z

r? @fee1-dead

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fee1-dead · 2026-02-17T01:17:09Z

@bors try

Gate #![reexport_test_harness_main] properly

rust-bors · 2026-02-17T03:27:13Z

☀️ Try build successful (CI)
Build commit: 79452e8 (79452e8441468c5568c20bfca2aa1fe75b645b2d, parent: 3c9faa0d037b9eecda4a440cc482ff7f960fb8a5)

JonathanBrouwer · 2026-02-17T06:28:00Z

@craterbot check

craterbot · 2026-02-17T06:28:31Z

👌 Experiment pr-152210 created and queued.
🤖 Automatically detected try build 79452e8
🔍 You can check out the queue and this experiment's details.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

fee1-dead · 2026-02-17T17:58:06Z

(for reference, this was discussed in #t-compiler > MCP needed for gating an accidentally stable attribute?)

craterbot · 2026-02-17T20:27:57Z

🚧 Experiment pr-152210 is now running

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

craterbot · 2026-02-19T16:14:56Z

🎉 Experiment pr-152210 is completed!
📊 6 regressed and 8 fixed (818761 total)
📊 2503 spurious results on the retry-regressed-list.txt, consider a retry¹ if this is a significant amount.
📰 Open the summary report.

⚠️ If you notice any spurious failure please add them to the denylist!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

re-run the experiment with crates=https://crater-reports.s3.amazonaws.com/pr-152210/retry-regressed-list.txt ↩

JonathanBrouwer · 2026-02-20T09:05:49Z

All changes in the crater run are spurious.
@rust-lang/lang are you ok with this change?
r=me if you are

traviscross · 2026-02-25T17:41:48Z

We talked about this in the meeting today. Let's propose to do this. Some people may do some further investigation; if we find things, we'll file concerns.

@rfcbot fcp merge lang

rust-rfcbot · 2026-02-25T17:43:41Z

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

steffahn · 2026-02-25T17:57:45Z

If anyone wonders the history, I tracked the git blame: the original marker as explicitly “ungated” came in https://github.com/rust-lang/rust/pull/28077/changes#diff-67980357baa8318a775fe4bc05336ea3feba90a64b58d0f8259e2665b2a719dbR237; the fixme comment was introduced in https://github.com/rust-lang/rust/pull/63824/changes#diff-2a0098fbcad74c47eafa44fd374d9f5740476a3af0134d9ec1bdc33e736a8063R188

RalfJung · 2026-02-25T18:01:26Z

the original marker as explicitly “ungated” came in

That just made the default explicit, didn't it? Adding it ungated happened in #22364.

jackh726 · 2026-02-25T18:03:14Z

Ah, I got nerd-sniped (oh well).

This attribute has been around since pre 1.0, and when feature-gated attributes were added (#22364), this just wasn't gated. The FIXME was added in #63824 alongside general other cleanups/refactors.

jackh726 · 2026-02-25T18:04:47Z

This seems like an obvious case of "this probably wasn't a vetted stabilization", and given that it seems like this attribute shouldn't be used without test_runner, adding a feature gate seems obviously appropriate.

Ozzy1423 · 2026-03-04T08:36:58Z

Rebased

rust-rfcbot · 2026-03-07T17:44:16Z

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

JonathanBrouwer · 2026-03-07T17:49:31Z

@bors r+ rollup

rust-bors · 2026-03-07T17:49:33Z

📌 Commit 4af572d has been approved by JonathanBrouwer

It is now in the queue for this repository.

…uwer Rollup of 2 pull requests Successful merges: - #153462 (Bootstrap update) - #152210 (Gate #![reexport_test_harness_main] properly)

Rollup merge of #152210 - Ozzy1423:attrs7, r=JonathanBrouwer Gate #![reexport_test_harness_main] properly Address the FIXME Removed from `issue-43106-gating-of-builtin-attrs.rs` since that is for stable attributes only. This would be a breaking change, search of github shows it is mostly but not always used with `#![test_runner]` which is already gated correctly. Details: #50297 Feel free to close this issue if you think it is not worth addressing the FIXME...

…uwer Rollup of 2 pull requests Successful merges: - rust-lang/rust#153462 (Bootstrap update) - rust-lang/rust#152210 (Gate #![reexport_test_harness_main] properly)

rustbot assigned fee1-dead Feb 6, 2026

fmease added needs-fcp This change is insta-stable, or significant enough to need a team FCP to proceed. needs-crater This change needs a crater run to check for possible breakage in the ecosystem. labels Feb 6, 2026

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rust-bors bot pushed a commit that referenced this pull request Feb 17, 2026

Auto merge of #152210 - Ozzy1423:attrs7, r=<try>

79452e8

Gate #![reexport_test_harness_main] properly

craterbot added S-waiting-on-crater Status: Waiting on a crater run to be completed. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 17, 2026

craterbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-crater Status: Waiting on a crater run to be completed. labels Feb 19, 2026

JonathanBrouwer added the relnotes Marks issues that should be documented in the release notes of the next release. label Feb 20, 2026

rustbot mentioned this pull request Feb 20, 2026

Tracking issue for release notes of #152210: Gate #![reexport_test_harness_main] properly #152894

Open

JonathanBrouwer added T-lang Relevant to the language team I-lang-nominated Nominated for discussion during a lang team meeting. I-lang-easy-decision Issue: The decision needed by the team is conjectured to be easy; this does not imply nomination labels Feb 20, 2026

traviscross added the P-lang-drag-1 Lang team prioritization drag level 1. https://rust-lang.zulipchat.com/#narrow/channel/410516-t-lang label Feb 20, 2026

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rust-rfcbot added final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. and removed proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. labels Feb 25, 2026

Gate #![reexport_test_harness_main] properly

4af572d

Ozzy1423 force-pushed the attrs7 branch from abb5229 to 4af572d Compare March 4, 2026 08:36

rust-bors bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Mar 7, 2026

JonathanBrouwer mentioned this pull request Mar 7, 2026

Rollup of 2 pull requests #153544

Merged

rust-bors bot merged commit 0da3785 into rust-lang:main Mar 7, 2026
11 checks passed

rustbot added this to the 1.96.0 milestone Mar 7, 2026

Ozzy1423 deleted the attrs7 branch March 8, 2026 08:34

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