[Alonely0]

Previously, the waiting loop would not handle SIGTTIN, SIGTTOU, and other signals; this was observed on commands that intercepted them on timeout if the child process required them for termination (or other behaviors). For example, it would hang on strace when the child was cat or tee, same as when trapping them on a subshell.

Note that this old behavior matched our implementation before the backend changes of my previous PR. Now that we have fine-grained control on signal handling, we can trivially match GNU and resolve the linked issue.

The new behavior matches GNU by continuing to wait on terminal job-control signals and forwarding the others on demand.

Fixes: #12979

[codspeed]

Merging this PR will not alter performance

1 warning, 1 note

⚠️ 118 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

ℹ️ 1 benchmark has no flamegraph

The flamegraph wasn't generated: most of the time was spent in runtime internals, which would leave nothing useful to analyze.

See affected benchmarks

✅ 401 untouched benchmarks
⏩ 70 skipped benchmarks¹

---

_{Comparing Alonely0:fix-timeout-strace (cefdd78) with main (1d6ca65)²}

Footnotes

1. 70 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (24f90f5) during the generation of this report, so 1d6ca65 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/tail/tail-n0f (passes in this run but fails in the 'main' branch)

[Copilot]

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Copilot review overview

2 open issues

• If the intent is to ‘continue waiting on terminal job-control signals’, SIGTSTP is also a… · New
• This test doesn’t assert an expected outcome (exit code/output), and as written it’s not clear it… · New

What changed in this PR

Updates timeout’s Unix signal-wait behavior to avoid stalling when terminal job-control signals are received, aligning behavior more closely with GNU timeout and addressing #12979.

Changes:

• Treat SIGTTIN/SIGTTOU as “continue waiting” signals in the wait loop.
• Expand the signal set used by timeout to include additional signals.
• Add a Unix-only regression test intended to cover terminal job-control signal handling.

File	Description
tests/​by-util/​test_timeout.rs	Adds a new Unix-only test exercising timeout behavior under SIGTTIN trapping.
src/​uucore/​src/​lib/​features/​process/​unix.rs	Updates wait-loop signal handling and expands the timeout signal set.

_{Review effort: Lite}

[Copilot]

Warning

Copilot couldn't run its full agentic review because it didn't start before the timeout. Make sure your repository has a runner available, or add a copilot-code-review.yml file specifying one with the runs-on attribute. See the docs for more details.

Copilot review overview

1 open issue

• This test currently doesn’t assert or execute an outcome beyond configuring a timeout; if… · New

2 resolved since last review

• This test doesn’t assert an expected outcome (exit code/output), and as written it’s not clear it…
• If the intent is to ‘continue waiting on terminal job-control signals’, SIGTSTP is also a…

_{Review effort: Lite}

[Copilot]

Warning

Copilot couldn't run its full agentic review because it didn't start before the timeout. Make sure your repository has a runner available, or add a copilot-code-review.yml file specifying one with the runs-on attribute. See the docs for more details.

Copilot review overview

3 open issues

• With sigwait-style handling, receiving SIGTTIN/SIGTTOU/SIGTSTP here will consume the signal… · New
• Hard-coding /bin/sh and /bin/cat can make the test fail in environments where those paths don’t… · New
• This test appears unlikely to exercise the new behavior: trap ... SIGTTIN applies to the shell,… · New

1 resolved since last review

• This test currently doesn’t assert or execute an outcome beyond configuring a timeout; if…

_{Review effort: Lite}