Sometimes roslyn fails to build in the VMR because of a race condition:

CSC : error CS2012: Cannot open 'D:\a_work\1\vmr\src\roslyn\artifacts\obj\SemanticSearch.ReferenceAssemblies\Release\net8.0\SemanticSearch.ReferenceAssemblies.dll' for writing -- 'The process cannot access the file 'D:\a_work\1\vmr\src\roslyn\artifacts\obj\SemanticSearch.ReferenceAssemblies\Release\net8.0\SemanticSearch.ReferenceAssemblies.dll' because it is being used by another process.' [D:\a_work\1\vmr\src\roslyn\src\Tools\SemanticSearch\ReferenceAssemblies\SemanticSearch.ReferenceAssemblies.csproj]

Example build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=669255&view=logs&jobId=9050e078-31bf-5111-d8ec-8b6fa95caf9c&j=9050e078-31bf-5111-d8ec-8b6fa95caf9c&t=523d8a07-ca4d-5c7a-367a-d86c5fc4038b

This is probably due to the project being built twice with the same outputs (an anti-pattern in msbuild). The binlog should tell. @jaredpar who would be a good person on the roslyn team to take a look?