Specifying RuntimeIdentifier causes the CodeCompiler to fail

[Ethereal77]

I have a project that uses TemplateGenerator to process template files. Whenever the project is just compiled with the net6.0 TFM but no RID, the project runs without problems.

However, if I specify the RuntimeIdentifier win-x64, it causes the runtime assembly System.Core.dll to be copied to the output directory. As the logic to decide if the host is a .NET Core one is based on comparing the directory name, and checking if dotnet.exe exists there, it fails because this is not the directory where the .NET SDK is installed.