Fix bootstrap rust build failure for vxworks

[gautam899]

Fixes #153332

Starting with VxWorks 25.09, struct stat was updated to use struct timespec instead of time_t for timestamp fields.

The following changes were made in libc in the commit libc.

As a result, when performing a bootstrap build with VxWorks ≥ 25.09, libc no longer exposes the fields st_mtime, st_atime, and st_ctime, as they are conditionally compiled in src/vxworks/mod.rs here libc. This causes the build to fail.

For VxWorks versions earlier than 25.09, the build completes successfully without errors.

This PR resolves the issue by detecting the WIND_RELEASE_ID environment variable (which is set in the VxWorks build environment) and conditionally guarding the affected functions in the two additional files where the errors originate.

[rustbot]

r? @Mark-Simulacrum

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[gautam899]

ping @biabbas

[Mark-Simulacrum]

Can you add documentation for the environment variable to https://doc.rust-lang.org/nightly/rustc/platform-support/vxworks.html?

cc rust-lang/rfcs#3750 as well, which seems like the long term solution here

[gautam899]

Can you add documentation for the environment variable to https://doc.rust-lang.org/nightly/rustc/platform-support/vxworks.html?

cc rust-lang/rfcs#3750 as well, which seems like the long term solution here

Hi @Mark-Simulacrum, I don't think there is a need to add documentation about the environment variable since this is set by vxworks workbench itself. The user is not required to set this environment variable from their end.

[gautam899]

@rustbot ready

[tgross35]

Hi @Mark-Simulacrum, I don't think there is a need to add documentation about the environment variable since this is set by vxworks workbench itself. The user is not required to set this environment variable from their end.

It would be useful to have documented that it reads this env, even if it isn't meant to be set, since this is pretty uncommon.

[gautam899]

Hi @Mark-Simulacrum, I don't think there is a need to add documentation about the environment variable since this is set by vxworks workbench itself. The user is not required to set this environment variable from their end.

It would be useful to have documented that it reads this env, even if it isn't meant to be set, since this is pretty uncommon.

Cool. I'll go ahead and add some info about the environment variable.

[rustbot]

Some changes occurred in src/doc/rustc/src/platform-support

cc @Noratrieb

[rustbot]

This PR was rebased onto a different main 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.

[gautam899]

Hi @Mark-Simulacrum @tgross35 , I have added the documentation for the environment variable WIND_RELEASE_ID. Pls let me know if it would suffice.

[gautam899]

ping @Mark-Simulacrum @Noratrieb

[Mark-Simulacrum]

@bors r+

There's generally speaking no need to re-ping folks so aggressively. Reviews can and do take a week+ normally; this PR hasn't been open for that long, and the latest changes were made less than a week ago. Please be patient in the future :)

[rust-bors]

📌 Commit 24d86b5 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[gautam899]

@bors r+

There's generally speaking no need to re-ping folks so aggressively. Reviews can and do take a week+ normally; this PR hasn't been open for that long, and the latest changes were made less than a week ago. Please be patient in the future :)

Apologies. I'll take care of that in the future.