NuGet - NU5131: References declared in the nuspec file are not being packaged

Question

I'm trying to reference two .dll files in a nupkg. I've added the files as references in the nuspec file:

<references>
   <reference file="Project.Modules.ModuleA.dll" />
   <reference file="Project.Modules.ModuleB.dll" />
</references>

When i try to pack, i get the following warning and the package does not include the referenced files.

WARNING: NU5131: References were found in the nuspec, but some reference assemblies were not found in both the nuspec and ref folder. Add the following reference assemblies: - Add Project.Modules.ModuleA.dll to the ref/any/ directory - Add Project.Modules.ModuleB.dll to the ref/any/ directory

Where do i place the files in order to get the package to include the required files?

Answer 1

Since I was using .net core 3.1, turns out all I had to do was to make some tweaks in the project.csproj file of the nupkg. Here's what I did:

Add an item group:

<ItemGroup>
    <ProjectReference Include="..\..\Project.Modules.ModuleA.csproj" >
      <PrivateAssets>all</PrivateAssets>
      <ReferenceOutputAssembly>true</ReferenceOutputAssembly>
      <IncludeAssets>Project.Modules.ModuleA.dll</IncludeAssets>
    </ProjectReference>
    <ProjectReference Include="..\Project.Modules.ModuleB.csproj" >
      <PrivateAssets>all</PrivateAssets>
      <ReferenceOutputAssembly>true</ReferenceOutputAssembly>
      <IncludeAssets>Project.Modules.ModuleB.dll</IncludeAssets>
    </ProjectReference>
  </ItemGroup>

Then add a target:

<Target DependsOnTargets="ResolveReferences" Name="CopyProjectReferencesToPackage">
    <ItemGroup>
      <BuildOutputInPackage Include="@(ReferenceCopyLocalPaths->WithMetadataValue('ReferenceSourceTarget', 'ProjectReference'))"/>
    </ItemGroup>
  </Target>

And finally add this inside the PropertyGroup element:

<TargetsForTfmSpecificBuildOutput>$(TargetsForTfmSpecificBuildOutput);CopyProjectReferencesToPackage</TargetsForTfmSpecificBuildOutput>

Works like a charm for me