Proj0033: Project reference includes should exist

<ItemGroup> can have node <ProjectReference> which defines an Include. This include should refer to exactly one file.

Non-compliant

When ../Benchmarks/Benchmarks.csproj does not exist.

<Project Sdk="Microsoft.NET.Sdk">

  <ItemGroup>
    <ProjectReference Include="../Benchmarks/Benchmarks.csproj" />
  </ItemGroup>
  
</Project>

Compliant

When ../Benchmarks/Benchmarks.csproj does exist.

<Project Sdk="Microsoft.NET.Sdk">

  <ItemGroup>
    <ProjectReference Include="../Benchmarks/Benchmarks.csproj" />
  </ItemGroup>

</Project>