This is a repository for a minimal reproduction of an issue with solution filters on the latest version of nuget. The problem is that nuget resolves the paths to the .csproj files in a solution filter. It evaluates them from the path of the solution filter rather than the path of the solution.

For example in this repository, I have a solution filter as src/nuget-slnf-bug/nuget-slnf-bug.slnf. It references the project src/nuget-slnf-bug/nuget-slnf-bug.csproj.

In the logs when it tries to resolve dependencies it tries to use the path src/nuget-slnf-bug/nuget-slnf-bug/nuget-slnf-bug.csproj and fails.

Failed NuGet Restore

In a github action, it shows the following result with nuget restore.

Run nuget restore src/nuget-slnf-bug/nuget-slnf-bug.slnf
MSBuild auto-detection: using msbuild version '15.0' from '/usr/lib/mono/msbuild/15.0/bin'.
WARNING: Project file /home/runner/work/nuget-slnf-bug/nuget-slnf-bug/src/nuget-slnf-bug/nuget-slnf-bug/nuget-slnf-bug.csproj cannot be found.
Nothing to do. None of the projects in this solution specify any packages for NuGet to restore.

It cannot find the .csproj file. Note the extra nuget-slnf-bug directory in the path output.

You can see this behavior in the .NET nuget restore GitHub actions workflow on this repository.

Successful Dotnet Restore

dotnet restore works fine for the same solution filter.

Run dotnet restore src/nuget-slnf-bug/nuget-slnf-bug.slnf
  Determining projects to restore...
  Restored /home/runner/work/nuget-slnf-bug/nuget-slnf-bug/src/nuget-slnf-bug/nuget-slnf-bug.csproj (in 2.15 sec).

It can find the .csproj file.

You can see this behavior in the .NET dotnet restore GitHub actions workflow on this repository.