[ci-scan] Build break: iossimulator-arm64 Mono fails compiling conditionvariable.c — undeclared pthread_cond_timedwait_relative_ [Content truncated due to length]

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Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1569716
Build error leg or test failing: iossimulator-arm64 Release AllSubsets_Mono - Build product (src/native/minipal/conditionvariable.c)

KBE authoring guidance (ci-failure-scan)

• Error Details is for readers. Paste the full exception, stack trace, or build error excerpt so the failure is understandable without opening the raw log.
• Build Analysis parses only the single JSON block under Error Message.
• ErrorMessage is a case-sensitive ordinal String.Contains substring copied verbatim from the failing log.
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Error Details

The runtime-extra-platforms pipeline (definition 154) fails to build the Mono runtime for iossimulator-arm64 because pthread_cond_timedwait_relative_np is called without a declaration. The compiler treats the implicit function declaration as an error (-Werror=implicit-function-declaration), breaking the minipal_objects target and thus Build product.

The failure is stable: absent from build 1567845 (2026-08-26), first seen in build 1569716 (2026-08-27), and still present in the follow-up build 1571812 (2026-08-28). It originates in src/native/minipal/conditionvariable.c:115, guarded by #if HAVE_CLOCK_GETTIME_NSEC_NP.

[45/388] Building C object mono/minipal/minipal/CMakeFiles/minipal_objects.dir/conditionvariable.c.o
/Users/runner/work/1/s/src/native/minipal/conditionvariable.c:115:17: error: call to undeclared function 'pthread_cond_timedwait_relative_np'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    115 |         error = pthread_cond_timedwait_relative_np(&condition->_impl, mutex, &timeout);
1 error generated.
##[error]src/mono/mono.proj(572,5): error MSB3073: The command " cmake --build . --target install --config Release" exited with code 1.

Error Message

{
  "ErrorMessage": "conditionvariable.c:115:17: error: call to undeclared function 'pthread_cond_timedwait_relative_np'",
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Agentic workflow metadata (ci-failure-scan)

Workflow artifact: ci-failure-scan
Artifact kind: kbe-verification
Verified match count: 1 hit in failure.log
First build it occurred: 1569716 (2026-08-27)

Generated by CI Outer-Loop Failure Scanner · opus48 · 907.6 AIC · ⌖ 11.7 AIC · ⊞ 20.7K · ◷

Report

Build	Repository	Step Name	Console log	Pull Request
1573540	dotnet/runtime	Build product	Log

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
1	1	1