Write reference assemblies to intermediate output

The .NET SDK now writes reference assemblies to the IntermediateOutputPath instead of the OutDir by default. This change removes these build-time-only artifacts from outputs that you require at run time.

Version introduced

.NET SDK 6.0.200

Old behavior

Since reference assemblies were added, the .NET SDK has written reference assemblies to the ref directory in the OutDir directory of the compilation. In .NET 5, the ProduceReferenceAssembly property was introduced and defaulted to true for net5.0 and later applications. With this change, many applications began implicitly generating reference assemblies in the OutDir directory.

New behavior

Now, reference assemblies are written to the refint directory of the IntermediateOutputPath directory by default, like many other intermediate artifacts.

Reason for change

Reference assemblies are generally not run-time assets, and so don't belong in the OutDir directory by default.

Recommended action

If you have custom build logic and you need to manipulate the reference assemblies, use the TargetRefPath property to get the correct path.

If an external system requires the reference assembly in OutDir, set the MSBuild property ProduceReferenceAssemblyInOutDir to true in your project file.