.NET 8 - Common Language Runtime detected an invalid program.

[VeroniqueBorel]

Hi,

My tests won't run when I try to migrate my test project to .NET 8. I get the same issue with a brand new project: in VS 2022 17.8.5, add a new project using template "xUnit Test Project" and framework .NET 8.0, then just run "Test1". The test doesn't run and I get this output:

Building Test Projects
Executing test method: TestProject2.UnitTest1.Test1
========== Starting test run ==========
An exception occurred while invoking executor 'executor://xunit/VsTestRunner2/netcoreapp': Common Language Runtime detected an invalid program.
Stack trace:
   at System.Collections.Generic.ValueListBuilder`1.TryCopyTo(Span`1 destination, Int32& itemsWritten)
   at System.Number.<TryFormatInt32>g__TryFormatInt32Slow|42_0[TChar](Int32 value, Int32 hexMask, ReadOnlySpan`1 format, IFormatProvider provider, Span`1 destination, Int32& charsWritten)
   at System.Int32.TryFormat(Span`1 destination, Int32& charsWritten, ReadOnlySpan`1 format, IFormatProvider provider)
   at System.DateTimeFormat.FormatFraction[TChar](ValueListBuilder`1& result, Int32 fraction, ReadOnlySpan`1 fractionFormat)
   at System.Globalization.TimeSpanFormat.FormatCustomized[TChar](TimeSpan value, ReadOnlySpan`1 format, DateTimeFormatInfo dtfi, ValueListBuilder`1& result)
   at System.Globalization.TimeSpanFormat.TryFormat[TChar](TimeSpan value, Span`1 destination, Int32& charsWritten, ReadOnlySpan`1 format, IFormatProvider formatProvider)
   at System.TimeSpan.TryFormat(Span`1 destination, Int32& charsWritten, ReadOnlySpan`1 format, IFormatProvider formatProvider)
   at System.Text.ValueStringBuilder.AppendFormatHelper(IFormatProvider provider, String format, ReadOnlySpan`1 args)
   at System.String.FormatHelper(IFormatProvider provider, String format, ReadOnlySpan`1 args)
   at System.String.Format(String format, Object arg0, Object arg1, Object arg2)
   at LoggerHelper.SendMessage(TestMessageLevel level, String assemblyName, String message) in /_/src/xunit.runner.visualstudio/Utility/LoggerHelper.cs:line 66
   at LoggerHelper.Log(String format, Object[] args) in /_/src/xunit.runner.visualstudio/Utility/LoggerHelper.cs:line 20
   at Xunit.Runner.VisualStudio.VsTestRunner.PrintHeader(LoggerHelper loggerHelper) in /_/src/xunit.runner.visualstudio/VsTestRunner.cs:line 127
   at Xunit.Runner.VisualStudio.VsTestRunner.Microsoft.VisualStudio.TestPlatform.ObjectModel.Adapter.ITestExecutor.RunTests(IEnumerable`1 tests, IRunContext runContext, IFrameworkHandle frameworkHandle) in /_/src/xunit.runner.visualstudio/VsTestRunner.cs:line 194
   at Microsoft.VisualStudio.TestPlatform.Common.ExtensionDecorators.SerialTestRunDecorator.RunTests(IEnumerable`1 tests, IRunContext runContext, IFrameworkHandle frameworkHandle)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Execution.RunTestsWithTests.InvokeExecutor(LazyExtension`2 executor, Tuple`2 executorUri, RunContext runContext, IFrameworkHandle frameworkHandle)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Execution.BaseRunTests.RunTestInternalWithExecutors(IEnumerable`1 executorUriExtensionMap, Int64 totalTests)

========== Test run finished: 0 Tests (0 Passed, 0 Failed, 0 Skipped) run in 214 ms ==========

Upgrading the NuGet packages to the latest version doesn't make any difference.

Did I miss something when I upgraded Visual Studio? Is .NET 8 supported?
Thank you for your help.

[bradwilson]

Out of the box version works:

Newest version works as well:

[VeroniqueBorel]

Thank you so much for checking. Your answer made me realize I had the profiler of Telerik JustMock running and it was indeed the culprit. Luckily the latest version is fixed.