Unhandled Exception: System.InvalidOperationException: Collection was modified after the enumerator was instantiated.
   at System.Collections.Generic.Stack`1.Enumerator.MoveNext()
   at Xunit.Sdk.DisposalTracker.Dispose() in C:\Dev\xunit\xunit\src\xunit.execution\Sdk\DisposalTracker.cs:line 26
   at Xunit.Sdk.ExtensibilityPointFactory.Dispose() in C:\Dev\xunit\xunit\src\xunit.execution\Sdk\ExtensibilityPointFactory.cs:line 54
   at Xunit.Sdk.TestFramework.Dispose() in C:\Dev\xunit\xunit\src\xunit.execution\Sdk\Frameworks\TestFramework.cs:line 49
   at System.Threading.ThreadPoolWorkQueue.Dispatch()