ThreadPoolTests.CooperativeBlockingCanCreateThreadsFaster failed on 10.0 on Windows

[svick]

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1483230
Build error leg or test failing: System.Threading.ThreadPools.Tests.ThreadPoolTests.CooperativeBlockingCanCreateThreadsFaster
Pull request: #129875

Error Message

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Fill the error message using step by step known issues guidance.

{
  "ErrorMessage": ["CooperativeBlockingCanCreateThreadsFaster [FAIL]", "Xunit.Sdk.TrueException: Assert.True() Failure"],
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Exception Message
Microsoft.DotNet.RemoteExecutor.RemoteExecutionException : Remote process failed with an unhandled exception.
CallStack
Child exception:
  Xunit.Sdk.TrueException: Assert.True() Failure
Expected: True
Actual:   False
   at System.Threading.ThreadPools.Tests.ThreadPoolTests.<>c.<CooperativeBlockingCanCreateThreadsFaster>b__38_0() in /_/src/libraries/System.Threading.ThreadPool/tests/ThreadPoolTests.cs:line 962
   at System.RuntimeMethodHandle.InvokeMethod(ObjectHandleOnStack target, Void** arguments, ObjectHandleOnStack sig, BOOL isConstructor, ObjectHandleOnStack result)
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor) in /_/src/coreclr/System.Private.CoreLib/src/System/RuntimeHandles.cs:line 1168
   at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args) in /_/src/coreclr/System.Private.CoreLib/src/System/Reflection/MethodBaseInvoker.CoreCLR.cs:line 36
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr) in /_/src/libraries/System.Private.CoreLib/src/System/Reflection/MethodBaseInvoker.cs:line 57
Child process:

System.Threading.ThreadPool.Tests, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51 System.Threading.ThreadPools.Tests.ThreadPoolTests+<>c Void <CooperativeBlockingCanCreateThreadsFaster>b__38_0()

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1483230
Error message validated: [CooperativeBlockingCanCreateThreadsFaster [FAIL] Xunit.Sdk.TrueException: Assert.True() Failure]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 6/29/2026 12:32:14 PM UTC

Report

Build	Repository	Test	Pull Request
1485786	dotnet/runtime	System.Threading.ThreadPools.Tests.ThreadPoolTests.CooperativeBlockingCanCreateThreadsFaster
1483230	dotnet/runtime	System.Threading.ThreadPools.Tests.ThreadPoolTests.CooperativeBlockingCanCreateThreadsFaster	#129875

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
0	2	2

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