std: use skip_unsupported_miri_tests to control when tests should be skipped in Miri due to missing shims by RalfJung · Pull Request #165117 · rust-lang/rust

RalfJung · 2026-10-29T09:35:36Z

We currently run some subset of std tests in Miri, skipping some because Miri doesn't support the operations they need. That is based on filters in the makefile. People don't know what is actually being tested and add random cfg(miri) in places to disable tests that were never run. This makes it quite hard to track which tests are being skipped and which operations we should add in Miri to get 100% std coverage. So let's replace that string-based filter with a cfg flag, skip_unsupported_miri_tests, that can be annotated at the tests.

Unfortunately I can't figure out how to disable all doctests in a module based on a cfg flag, so this entirely disables std doctests being run in Miri in our CI. (We still run them in https://github.com/rust-lang/miri-test-libstd.)

See prior discussion on Zulip.
Docs PR: rust-lang/std-dev-guide#86

r? @tgross35
try-job: test-x86_64-gnu-aux

rustbot · 2026-10-29T09:35:39Z

Any special-casing of Miri in the standard library requires review.

cc @rust-lang/miri

rustbot · 2026-10-29T09:35:42Z

tgross35 is currently at their maximum review capacity.
They may take a while to respond.

RalfJung · 2026-10-29T09:36:17Z

@bors try

std: use skip_missing_miri_shims to control when tests should be skipped in Miri due to missing shims try-job: test-x86_64-gnu-aux

tgross35 · 2026-10-29T11:21:37Z

I'm pretty okay with this, @rust-lang/libs-ping any thoughts? See the Zulip discussion linked in the top post for context

rust-bors · 2026-10-29T12:19:15Z

☀️ Try build successful (CI)
Build commit: ea60bf0 (ea60bf0be95c912404a2821f1c21a97850d94d6e)
Base parent: ce37c4f (ce37c4ff837c5c5dc45cddf9e1e3704e42ca67ea)

RalfJung · 2026-10-31T10:28:41Z

    /// Converts a `BorrowedFd` into a reference to a file-like type.
    ///
-    #[cfg_attr(all(unix, not(miri)), doc = "```")]
+    #[cfg_attr(unix, doc = "```")]


I screwed this up in #164963...

View changes since the review

RalfJung · 2026-11-07T10:32:02Z

I'm pretty okay with this, @rust-lang/libs-ping any thoughts? See the Zulip discussion linked in the top post for context

It's been a week -- seems like nobody has major concerns?

…uwer Rollup of 16 pull requests Successful merges: - #165575 (Upgrade bundled musl to 1.2.6) - #163992 (add `core::arch::{x86, x86_64}::x87_f80`) - #165117 (std: use skip_unsupported_miri_tests to control when tests should be skipped in Miri due to missing shims) - #165458 (fix incorrect byte count suffix on MSVC) - #165490 (Mark the compile unit for `-Zdebuginfo-for-profiling`) - #165586 (Remove `backend_optimization_level`.) - #165646 (fix NumScalableVectors::from_field_count) - #165655 (Unignore passing GCC backend tests) - #165740 (miri subtree update) - #153261 (Partially stabilize `ptr_alignment_type` as `alignment_type`) - #164559 (Windows: fix Dir::remove and Dir::rename following symlinks) - #165682 (interpret: ensure newly created unions have uninit in their padding) - #165693 (Move `check_attr` to attribute parsing) - #165715 (windows: check for null before wide encoding) - #165717 (mpsc_sync::stream_send_recv_stress: wait for all threads to finish) - #165733 (docs(num): remove needless whitespaces) Failed merges: - #165727 (Normalize "beta release channel" in `const-supertrait-unstable` test) - #164218 (Tweak private re-export errors to point at correct span and have more context) - #165709 (remove 'x miri' smoke test from PR CI)

@ghost

miri subtree update Fixes an issue in `socketpair` to unblock rust-lang/rust#165117. Subtree update of `miri` to rust-lang@57677a1. Created using https://github.com/rust-lang/josh-sync. r? @ghost

@tgross35

…r=maxdexh std: use skip_unsupported_miri_tests to control when tests should be skipped in Miri due to missing shims We currently run some subset of std tests in Miri, skipping some because Miri doesn't support the operations they need. That is based on filters in the makefile. People don't know what is actually being tested and add random `cfg(miri)` in places to disable tests that were never run. This makes it quite hard to track which tests are being skipped and which operations we should add in Miri to get 100% std coverage. So let's replace that string-based filter with a cfg flag, `skip_unsupported_miri_tests`, that can be annotated at the tests. Unfortunately I can't figure out how to disable all doctests in a module based on a cfg flag, so this entirely disables std doctests being run in Miri in our CI. (We still run them in https://github.com/rust-lang/miri-test-libstd.) See prior discussion [on Zulip](https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/Miri.20vs.20tests.20in.20std/with/635913743). Docs PR: rust-lang/std-dev-guide#86 r? @tgross35 try-job: test-x86_64-gnu-aux

RalfJung · 2026-11-10T14:00:10Z

@JonathanBrouwer I suspect this is actually the one that made the rollup fail.

@bors try jobs=test-x86_64-msvc-ext2

std: use skip_unsupported_miri_tests to control when tests should be skipped in Miri due to missing shims try-job: test-x86_64-msvc-ext2

RalfJung · 2026-11-10T14:01:51Z

Yeah I forgot to update this.

@bors r-

rust-bors · 2026-11-10T14:02:06Z

This pull request was unapproved.

This PR was contained in a rollup (#165756), which was unapproved.

View changes since this unapproval

RalfJung · 2026-11-10T14:08:54Z

Let's just wait for #165709 to go in first.

rust-bors · 2026-11-10T15:51:22Z

💔 Test for 6527c4d failed: CI. Failed job:

try - test-x86_64-msvc-ext2 (web logs, enhanced plaintext logs)

…ts should be skipped in Miri due to missing shims

rustbot · 2026-11-10T20:34:59Z

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.

RalfJung · 2026-11-10T20:35:35Z

@bors r=maxdexh

rust-bors · 2026-11-10T20:35:39Z

📌 Commit e982cc3 has been tentatively approved by maxdexh

It will be put into the queue for this repository once PR CI succeeds.

maxdexh · 2026-11-10T20:37:42Z

Fastest rebase in the west

rust-bors · 2026-11-11T03:51:05Z

⌛ Testing commit e982cc3 with merge 9a513ad...

Workflow: https://github.com/rust-lang/rust/actions/runs/42955422759

@tgross35

std: use skip_unsupported_miri_tests to control when tests should be skipped in Miri due to missing shims We currently run some subset of std tests in Miri, skipping some because Miri doesn't support the operations they need. That is based on filters in the makefile. People don't know what is actually being tested and add random `cfg(miri)` in places to disable tests that were never run. This makes it quite hard to track which tests are being skipped and which operations we should add in Miri to get 100% std coverage. So let's replace that string-based filter with a cfg flag, `skip_unsupported_miri_tests`, that can be annotated at the tests. Unfortunately I can't figure out how to disable all doctests in a module based on a cfg flag, so this entirely disables std doctests being run in Miri in our CI. (We still run them in https://github.com/rust-lang/miri-test-libstd.) See prior discussion [on Zulip](https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/Miri.20vs.20tests.20in.20std/with/635913743). Docs PR: rust-lang/std-dev-guide#86 r? @tgross35 try-job: test-x86_64-gnu-aux

Zalathar · 2026-11-11T04:01:03Z

@bors yield (enclosing rollup)

rust-bors · 2026-11-11T04:01:07Z

Auto build was cancelled. Cancelled workflows:

https://github.com/rust-lang/rust/actions/runs/42955422759

The next pull request likely to be tested is #165793.

rustbot assigned tgross35 Oct 29, 2026