OverlappingExtensions_AllMatchTypes_Comprehensive failing on Assert.DoesNotContain

[elinor-fung]

System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive [FAIL]
  Assert.DoesNotContain() Failure: Filter matched in collection
               � (pos 0)
  Collection: ["C:\\h\\w\\B1E60A3B\\t\\#MatchTypesTests_Directory_"���, "C:\\h\\w\\B1E60A3B\\t\\#MatchTypesTests_Directory_"���, "C:\\h\\w\\B1E60A3B\\t\\#MatchTypesTests_Directory_"���, "C:\\h\\w\\B1E60A3B\\t\\#MatchTypesTests_Directory_"���]
  Stack Trace:
    /_/src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/Enumeration/MatchTypesTests.cs(584,0): at System.IO.Tests.Enumeration.MatchTypesTests.OverlappingExtensions_AllMatchTypes_Comprehensive()
       at System.RuntimeMethodHandle.InvokeMethod(ObjectHandleOnStack target, Void** arguments, ObjectHandleOnStack sig, BOOL isConstructor, ObjectHandleOnStack result)
    /_/src/coreclr/System.Private.CoreLib/src/System/Reflection/MethodBaseInvoker.CoreCLR.cs(36,0): at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
    /_/src/libraries/System.Private.CoreLib/src/System/Reflection/RuntimeMethodInfo.cs(126,0): at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1441860
Build error leg or test failing: System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive
Pull request: #128796

Error Message

{
  "ErrorMessage": ["Assert.DoesNotContain() Failure: Filter matched in collection", "OverlappingExtensions_AllMatchTypes_Comprehensive"],
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1441860
Error message validated: [Assert.DoesNotContain() Failure: Filter matched in collection OverlappingExtensions_AllMatchTypes_Comprehensive [FAIL]]
Result validation: ❌ Known issue did not match with the provided build.
Validation performed at: 6/2/2026 5:02:10 PM UTC

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1441860
Error message validated: [Assert.DoesNotContain() Failure: Filter matched in collection OverlappingExtensions_AllMatchTypes_Comprehensive]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 6/2/2026 5:03:23 PM UTC

Report

Build	Repository	Test	Pull Request
1595439	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#133831
1589052	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#130407
1587471	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#133425
1586491	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#130050
1581856	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#132965
1580473	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#133111
1579855	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive
1577496	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#132932
1577137	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive
1575788	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#130849
1574216	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#132881
1573798	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#132923
1573125	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#132861
1566044	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#131655
1566016	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#132725
1565907	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#131474
1563629	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive
1563062	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive
1559981	dotnet/runtime	WasmTestOnChrome-ST-System.IO.FileSystem.Tests.WorkItemExecution
1559387	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#131265
1559111	dotnet/runtime	WasmTestOnChrome-CLR-ST-Batch-18.WorkItemExecution	#131866
1555424	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive	#132396
1555007	dotnet/runtime	System.IO.Tests.Enumeration.MatchTypesTests_DirectoryInfo_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
1	4	23

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[MihuBot]

I'm a bot. Here are possible related and/or duplicate issues (I may be wrong):

• Test failure: System.IO.Tests.Enumeration.MatchTypesTests_Directory_GetFiles.OverlappingExtensions_AllMatchTypes_Comprehensive #125313
• OverlappingExtensions_AllMatchTypes_Comprehensive failed in CI #124210

[adamsitnik]

I can see that #122947 was merged on Jan 26 and #123695 was merged on Feb 3 and this test failure was reported on Feb 10 in #124210 for the first time. And it reproduces quite frequently now.

@jozkee @jeffhandley I am moving it to 11 to make sure we spend some time investigating to ensure there is no regression similar to #130134

[jozkee]

This appears to be a flaky assertion rather than a regression.

runtime/src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/Enumeration/MatchTypesTests.cs

Line 584 in 1db0d83

Assert.DoesNotContain(win32Paths, p => p.Contains("foo"));

It checks the entire absolute path. In one failure, the randomized directory was /tmp/#MatchTypesTests_Directory_GetFiles_foopzs3q..., so every result contained foo. The assertion should compare the filenames or the exact expected paths.