IL1012: Unhandled exception. System.ArgumentOutOfRangeException: Length cannot be less than zero

[rolfbjarne]

Repro: linkertestcase-8e00d2e.zip

Download, extract and execute test.sh:

$ ./test.sh
+ test -n ''
+ LINKER=/usr/local/share/dotnet/sdk/5.0.100-rc.1.20411.10/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/illink.dll
+ test -f /usr/local/share/dotnet/sdk/5.0.100-rc.1.20411.10/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/illink.dll
+ /usr/local/share/dotnet/dotnet /usr/local/share/dotnet/sdk/5.0.100-rc.1.20411.10/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/illink.dll @testcase.rsp
ILLink: error IL1012: IL Linker has encountered an unexpected error. Please report the issue at https://github.com/mono/linker/issues
Fatal error in IL Linker
Unhandled exception. System.ArgumentOutOfRangeException: Length cannot be less than zero. (Parameter 'length')
   at System.String.Substring(Int32 startIndex, Int32 length)
   at Mono.Linker.TypeReferenceExtensions.GetDisplayNameWithoutNamespace(TypeReference type)
   at Mono.Linker.TypeReferenceExtensions.GetDisplayName(TypeReference type)
   at Mono.Linker.Dataflow.DiagnosticUtilities.GetGenericParameterDescriptionForErrorMessage(GenericParameter genericParameter)
   at Mono.Linker.Dataflow.DiagnosticUtilities.GetMetadataTokenDescriptionForErrorMessage(IMetadataTokenProvider targetContext)
   at Mono.Linker.Dataflow.ReflectionMethodBodyScanner.GetValueDescriptionForErrorMessage(ValueNode value)
   at Mono.Linker.Dataflow.ReflectionMethodBodyScanner.RequireDynamicallyAccessedMembers(ReflectionPatternContext& reflectionContext, DynamicallyAccessedMemberTypes requiredMemberTypes, ValueNode value, IMetadataTokenProvider targetContext)
   at Mono.Linker.Dataflow.ReflectionMethodBodyScanner.ProcessGenericArgumentDataFlow(GenericParameter genericParameter, TypeReference genericArgument, IMemberDefinition source)
   at Mono.Linker.Steps.MarkStep.MarkGenericArgumentConstructors(IGenericInstance instance, IMemberDefinition sourceLocationMember)
   at Mono.Linker.Steps.MarkStep.MarkGenericArguments(IGenericInstance instance, IMemberDefinition sourceLocationMember)
   at Mono.Linker.Steps.MarkStep.GetOriginalType(TypeReference type, DependencyInfo reason, IMemberDefinition sourceLocationMember)
   at Mono.Linker.Steps.MarkStep.MarkType(TypeReference reference, DependencyInfo reason, IMemberDefinition sourceLocationMember)
   at Mono.Linker.Steps.MarkStep.MarkField(FieldDefinition field, DependencyInfo& reason)
   at Mono.Linker.Steps.MarkStep.MarkEntireType(TypeDefinition type, Boolean includeBaseTypes, DependencyInfo& reason, IMemberDefinition sourceLocationMember)
   at Mono.Linker.Steps.MarkStep.MarkEntireType(TypeDefinition type, Boolean includeBaseTypes, DependencyInfo& reason, IMemberDefinition sourceLocationMember)
   at Mono.Linker.Steps.MarkStep.MarkEntireAssembly(AssemblyDefinition assembly)
   at Mono.Linker.Steps.MarkStep.InitializeAssembly(AssemblyDefinition assembly)
   at Mono.Linker.Steps.MarkStep.Initialize()
   at Mono.Linker.Steps.MarkStep.Process(LinkContext context)
   at Mono.Linker.Pipeline.Process(LinkContext context)
   at Mono.Linker.Driver.Run(ILogger customLogger)
   at Mono.Linker.Driver.Main(String[] args)
./test.sh: line 14: 47999 Abort trap: 6           /usr/local/share/dotnet/dotnet $LINKER @testcase.rsp