MultiThreadedGetExportsWorkWithImportingConstructor failed with NullReferenceException

[danmoseley]

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1343338
Build error leg or test failing: System.Composition.TypedParts.Tests.ReflectionTests.MultiThreadedGetExportsWorkWithImportingConstructor
Pull request: #124628

Error Message

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

{
  "ErrorMessage": ["MultiThreadedGetExportsWorkWithImportingConstructor", "NullReferenceException"],
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

leg=System.Composition.TypedParts.Tests.ReflectionTests.MultiThreadedGetExportsWorkWithImportingConstructor)
Failing Configuration
[AzureLinux.3.0.ArmArch.Open](https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1343338&view=ms.vss-test-web.build-test-results-tab&runId=37515930&resultId=111528)
Exception Message
System.AggregateException : One or more errors occurred. (Object reference not set to an instance of an object)
---- System.NullReferenceException : Object reference not set to an instance of an object
CallStack
   at System.Composition.TypedParts.Tests.ReflectionTests.MultiThreadedGetExportsWorkWithImportingConstructor() in /_/src/libraries/System.Composition.TypedParts/tests/ReflectionTests.cs:line 59
   at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args) in /_/src/mono/System.Private.CoreLib/src/System/Reflection/MethodBaseInvoker.Mono.cs:line 22
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr) in /_/src/libraries/System.Private.CoreLib/src/System/Reflection/MethodBaseInvoker.cs:line 57
----- Inner Stack Trace -----
   at System.Linq.Enumerable.Concat[ExportDescriptorProvider](IEnumerable`1 first, IEnumerable`1 second) in /_/src/libraries/System.Linq/src/System/Linq/Concat.cs:line 23
   at System.Composition.Hosting.CompositionHost.CreateCompositionHost(IEnumerable`1 providers) in /_/src/libraries/System.Composition.Hosting/src/System/Composition/Hosting/CompositionHost.cs:line 48
   at System.Composition.Hosting.CompositionHost.CreateCompositionHost(ExportDescriptorProvider[] providers) in /_/src/libraries/System.Composition.Hosting/src/System/Composition/Hosting/CompositionHost.cs:line 37
   at System.Composition.Hosting.ContainerConfiguration.CreateContainer() in /_/src/libraries/System.Composition.TypedParts/src/System/Composition/Hosting/ContainerConfiguration.cs:line 42
   at System.Composition.TypedParts.Tests.ReflectionTests.CreateContainer(Type[] types) in /_/src/libraries/System.Composition.TypedParts/tests/ReflectionTests.cs:line 88
   at System.Composition.TypedParts.Tests.ReflectionTests.GetExport() in /_/src/libraries/System.Composition.TypedParts/tests/ReflectionTests.cs:line 76

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1343338
Error message validated: [MultiThreadedGetExportsWorkWithImportingConstructor NullReferenceException]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 3/19/2026 9:51:51 PM UTC

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