Please note

This does not happen when running on Linux. The same exact project compiles and runs normally in any linux environment, but fails on Windows and macOS. This problem started seemingly spontaneously, and has been replicated on various dotnet SDK versions (including 5.0.204, 5.0.203, and 5.0.202).

I have also checked out old commits in my repo that are known to have compiled on macOS and Windows in the past, and they now show the same issue. This suggests something that has changed in the NuGet packages themselves, or some other external factor.

I have also posted about this here: https://stackoverflow.com/questions/68273070/c-sharp-source-generator-cannot-be-created

Version Used:

        <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.10.0" PrivateAssets="all" />
        <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.2" PrivateAssets="all" />

Steps to Reproduce:

1. Reference a source generation package like so:

    <ItemGroup>
        <ProjectReference Include="..\My.Company.ReportingModel.Generators\My.Company.ReportingModel.Generators.csproj">
            <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
            <OutputItemType>Analyzer</OutputItemType>
        </ProjectReference>
    </ItemGroup>

    <ItemGroup>
        <AdditionalFiles Include="../../models/*.yaml;../../models/*.yml" />
    </ItemGroup>

1. Run dotnet build.

Expected Behavior:

The solution builds normally.

Actual Behavior:

Build FAILED

CSC : warning CS8032: An instance of analyzer My.Company.Generators.ReportingV2Generator cannot be created from /Users/work/dev/git/reporting-model/src/My.Company.Generators/bin/Debug/netstandard2.1/My.Company.Generators.dll : Could not load file or assembly 'Microsoft.CodeAnalysis, Version=3.10.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.. [/Users/work/dev/git/reporting-model/src/My.Team.Models.ReportingV2/My.Team.Models.ReportingV2.csproj]

/Users/work/dev/git/reporting-model/src/My.Company.Api/SmokeTests/Tests/ContentAskExpertSmokeTest.cs(7,20): error CS0234: The type or namespace name 'Models' does not exist in the namespace 'My.Team' (are you missing an assembly reference?) [/Users/work/dev/git/reporting-model/src/My.Company.Api/My.Company.Api.csproj]
... Many more of the above "type or namespace" errors