Test failure: Interop Work Item throws System.IO.FileNotFoundException

[VincentBu]

Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594299

Build error leg or test failing: Interop Work Item

Error Detail:

Unhandled exception. System.IO.FileNotFoundException: Could not find assembly 'TypeMapLib1, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'. Either explicitly load this assembly using a method such as LoadFromAssemblyPath() or use a MetadataAssemblyResolver that returns a valid assembly.
   at System.Reflection.TypeLoading.Ecma.EcmaResolver.ResolveAssembly(AssemblyReferenceHandle handle, EcmaModule module) in /_/src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/General/Ecma/EcmaResolver.cs:line 150
   at System.Reflection.TypeLoading.Ecma.EcmaResolver.ComputeTypeRefResolution(TypeReferenceHandle handle, EcmaModule module) in /_/src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/General/Ecma/EcmaResolver.cs:line 77
   at System.Reflection.TypeLoading.Ecma.EcmaModule.GetTypeFromReference(MetadataReader reader, TypeReferenceHandle handle, Byte rawTypeKind) in /_/src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/Modules/Ecma/EcmaModule.TypeProvider.cs:line 20
   at System.Reflection.Metadata.Ecma335.SignatureDecoder`2.DecodeType(BlobReader& blobReader, Boolean allowTypeSpecifications, Int32 typeCode) in /_/src/libraries/System.Reflection.Metadata/src/System/Reflection/Metadata/Ecma335/SignatureDecoder.cs:line 127
   at System.Reflection.Metadata.Ecma335.SignatureDecoder`2.DecodeTypeSequence(BlobReader& blobReader) in /_/src/libraries/System.Reflection.Metadata/src/System/Reflection/Metadata/Ecma335/SignatureDecoder.cs:line 152
   at System.Reflection.Metadata.Ecma335.SignatureDecoder`2.DecodeType(BlobReader& blobReader, Boolean allowTypeSpecifications, Int32 typeCode) in /_/src/libraries/System.Reflection.Metadata/src/System/Reflection/Metadata/Ecma335/SignatureDecoder.cs:line 115
   at System.Reflection.TypeLoading.Ecma.EcmaResolver.ResolveTypeDefRefOrSpec(EntityHandle handle, EcmaModule module, TypeContext& typeContext) in /_/src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/General/Ecma/EcmaResolver.cs:line 19
   at System.Reflection.TypeLoading.Ecma.EcmaCustomAttributeData.ComputeAttributeType() in /_/src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/CustomAttributes/Ecma/EcmaCustomAttributeData.cs:line 54
   at System.Reflection.TypeLoading.RoCustomAttributeData.get_AttributeType() in /_/src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/CustomAttributes/RoCustomAttributeData.cs:line 15
   at AssemblyChecker.AssemblyInspector.IsDebug(String path) in /_/src/coreclr/tools/AssemblyChecker/AssemblyInspector.cs:line 20
   at AssemblyChecker.Program.Main(String[] args) in /_/src/coreclr/tools/AssemblyChecker/Program.cs:line 84
[createdump] Gathering state for process 66735 
[createdump] Crashing thread d63ab signal 6 (0006)
[createdump] Writing crash report to file /cores/coredump.66735.dmp.crashreport.json
[createdump] Crash report successfully written
[createdump] Writing minidump with heap to file /cores/coredump.66735.dmp
[createdump] Written 749564024 bytes (182999 pages) to core file
[createdump] Target process is alive
[createdump] Dump successfully written in 2674ms
waitpid() returned successfully (wstatus 00000000) WEXITSTATUS 0 WTERMSIG 0

Error Message

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

{
  "ErrorMessage": "Failed test: Interop Work Item",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594299
Error message validated: [Failed test: Interop Work Item]
Result validation: ❌ Known issue did not match with the provided build.
Validation performed at: 9/20/2026 2:23:57 AM UTC

Report

Build	Repository	Test	Pull Request
1594299	dotnet/runtime	Interop.WorkItemExecution

Summary

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

[dotnet-policy-service]

Tagging subscribers to this area: @steveisok, @dotnet/area-system-reflection
See info in area-owners.md if you want to be subscribed.

[steveisok]

I traced this to a regression introduced by #133202.

TypeMapLib1.dll is present beside TypeMapApp.dll in the Helix payload. The failure occurs because AssemblyChecker now uses MetadataLoadContext with a resolver that searches only the runtime directory, not the directory containing the inspected assembly. Resolving the TypeMap custom attributes therefore throws FileNotFoundException. This exact side-by-side dependency risk was identified during the review of #133202.

The exception does not directly fail the test wrapper. Instead, every abort generates a large crash dump. Repeated invocations produce several gigabytes of dumps, eventually exhausting the worker's disk and preventing IL round-trip files and test results from being written. This also explains why some runs appear green despite containing the same exceptions and dump storm: those machines had enough free disk space.

The fix should create a resolver for each inspected assembly that probes the assembly's directory before the runtime directory. A regression test should cover an assembly-level attribute whose type or generic argument is defined in an adjacent DLL.

Note

This analysis was generated with GitHub Copilot.