`DataTarget.CreateSnapshotAndAttach` fails to disassemble generic type in Windows/CoreCLR

[timcassell]

While working on dotnet/BenchmarkDotNet#2843, I found that using DataTarget.CreateSnapshotAndAttach in the same process fails to disassemble properly only on Windows and CoreCLR (.Net 8 in my case). It works fine in .Net Framework, and it also works fine in Linux. Thankfully it works with AttachToProcess in Windows, so I can use that as a workaround, but I figured I should raise this issue.

I tried 3.1.512801 and 4.0.0-beta.24360.3, same behavior on both.

The test that failed:

public class Generic<T> where T : new()
{
    [Benchmark]
    public T Create() => new T();
}

[Theory]
[MemberData(nameof(GetAllJits), DisableDiscoveryEnumeration = true)]
[Trait(Constants.Category, Constants.BackwardCompatibilityCategory)]
public void CanDisassembleGenericTypes(Jit jit, Platform platform, IToolchain toolchain)
{
    if (OsDetector.IsMacOS()) return; // currently not supported

    var disassemblyDiagnoser = new DisassemblyDiagnoser(
        new DisassemblyDiagnoserConfig(printSource: true, maxDepth: 3));

    CanExecute<Generic<int>>(CreateConfig(jit, platform, toolchain, disassemblyDiagnoser, RunStrategy.Monitoring));

    var result = disassemblyDiagnoser.Results.Values.Single();

    Assert.Empty(result.Errors);
    Assert.Contains(result.Methods, method => method.Maps.Any(map => map.SourceCodes.OfType<Asm>().Any()));
}

https://github.com/dotnet/BenchmarkDotNet/blob/1c3faa21ab9aac8aab277e1fd19e151768c57cba/tests/BenchmarkDotNet.IntegrationTests/DisassemblyDiagnoserTests.cs#L136-L159