Debugging XUnit test cases fails critically

[fredrikhr]

Here's my CSPROJ:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
    <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
    <RuntimeFrameworkVersion>1.1.0</RuntimeFrameworkVersion>
  </PropertyGroup>
  <PropertyGroup Label="BasePath">
    <BaseOutputPath>$(SolutionDir)bin\</BaseOutputPath>
    <BaseIntermediateOutputPath>$(SolutionDir)obj\$(MSBuildProjectName)\</BaseIntermediateOutputPath>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0-preview-20170222-09" />
    <PackageReference Include="xunit" Version="2.2.0" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />
  </ItemGroup>
</Project>

Note the (as of writing this issue) the newest versions for the Test SDK and XUnit packages. I'm using the newest RC for Visual Studio 2017 (Version 15.0.0-RC4+26206.0)

Also note that I'm setting the BaseOutputPath and BaseIntermediateOutputPath to values different from their defaults.

Running test cases from the Test Explorer view in Visual Studio works fine. However, when I choose to debug one or more tests, Visual Studio goes over into debugging mode, and immediately displays a crtical error message window:

A fatal error has occurred and debugging needs to be terminated. For more details, please see the Microsoft Help and Support web site. HRESULT=0x8000ffff. ErrorCode=0x0.

[adrianvmsft]

Indeed, the roslyn project system is the best place to ask this question as they own the overall C# experience in Visual Studio.