Nuget Exception while running Unit Testing example for Source Generator Testing

[papafe]

I was trying to setup my system to test source generators following the recommended approach (Solution A) in the roslyn cookbook . I have practically copy pasted the code, but I get the following exception when running the test:

NuGet.Protocol.Core.Types.FatalProtocolException : Unable to load the service index for source https://api.nuget.org/v3/index.json.
  ----> System.IO.FileLoadException : Could not load file or assembly 'Newtonsoft.Json, Version=9.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

I am a little confused by this exception, as the source generator project has no reference to external packages, while the test project uses NewtonSoft.Json version 13.0.1. I also don't have issues with Nuget otherwise.

I have tried also the non-recommended approach (Solution B), and that works fine.

I'm using:
Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.NUnit (1.1.1)

[sharwell]

This issue is caused by your test project declaring a reference to Newtonsoft.Json, and NuGet omitting a difference one (NuGet/Home#10505). To resolve this issue, you'll need to change the project to reference Newtonsoft.Json 9.0.0.0, or provide a binding redirect to the newer version it's using.

[sharwell]

Duplicate of NuGet/Home#10505