Unable to add LICENSE/README to NuGet package: error NU5030

Question

I have the following .targets file that I import in multiple .csproj projects:

<Project>
    <PropertyGroup>
        ...         
        <PackageLicenseFile>LICENSE</PackageLicenseFile>
        <PackageReadmeFile>README.md</PackageReadmeFile>
        ...         
    </PropertyGroup>
</Project>

Both LICENSE and README.md files are next to that .targets file which is at root of repository.

But I get the following error:

error NU5030: The license file 'C:\...\blah\LICENSE' does not exist in the package. [C:\...\blah\whatever\whatever.csproj]

Reference documentation:

• https://learn.microsoft.com/en-us/nuget/reference/msbuild-targets#packing-a-license-expression-or-a-license-file
• https://devblogs.microsoft.com/nuget/add-a-readme-to-your-nuget-package/

Question:

How can I get these two files packed onto the NuGet package?

Answer 1

Finally found the cause thanks to a clue in the docs though that wasn't enough to get it working.

Not only there must be ItemGroup as well but these shall have $(MSBuildThisFileDirectory):

<Project>

    <PropertyGroup>
        <PackageLicenseFile>LICENSE</PackageLicenseFile>
        <PackageReadmeFile>README.md</PackageReadmeFile>
    </PropertyGroup>

    <ItemGroup>
        <None Include="$(MSBuildThisFileDirectory)LICENSE" Pack="true" PackagePath="" />
        <None Include="$(MSBuildThisFileDirectory)README.md" Pack="true" PackagePath="" />
    </ItemGroup>

</Project>