MSBuild well-known item metadata and NuGet pack - msbuild

Question

I am trying to add custom files to a specific NuGet package (basically I need all output files included in the NuGet package since it serves as a tool for Chocolatey).
After some searching, I found this potential fix:
<PropertyGroup>
<TargetsForTfmSpecificBuildOutput>$(TargetsForTfmSpecificBuildOutput);GetToolsPackageFiles</TargetsForTfmSpecificBuildOutput>
</PropertyGroup>
<Target Name="GetToolsPackageFiles">
<ItemGroup>
<BuildOutputInPackage Include="$(OutputPath)\**\*.dll" />
<BuildOutputInPackage Include="$(OutputPath)\**\*.exe" />
</ItemGroup>
</Target>
Unfortunately, this won't work correctly for subdirectories, so I tried this:
<PropertyGroup>
<TargetsForTfmSpecificBuildOutput>$(TargetsForTfmSpecificBuildOutput);GetToolsPackageFiles</TargetsForTfmSpecificBuildOutput>
</PropertyGroup>
<Target Name="GetToolsPackageFiles">
<ItemGroup>
<BuildOutputInPackage Include="$(OutputPath)\**\*.dll">
<TargetPath>$([MSBuild]::MakeRelative('$(OutputPath)', %(FullPath)))</TargetPath>
</BuildOutputInPackage>
<BuildOutputInPackage Include="$(OutputPath)\**\*.exe">
<TargetPath>$([MSBuild]::MakeRelative('$(OutputPath)', %(FullPath)))</TargetPath>
</BuildOutputInPackage>
</ItemGroup>
</Target>
According to the docs, I should be able to use %(FullPath), but I am getting this error:
error MSB4184: The expression "[MSBuild]::MakeRelative(C:\Sour
ce\RepositoryCleaner\output\Release\RepositoryCleaner\netcoreapp3.1\, '')" cannot be evaluated. Parameter "path" cannot have zero length.
[C:\Source\RepositoryCleaner\src\RepositoryCleaner\RepositoryCleaner.csproj]
Any idea why the well-known items don't seem to work in this scenario?

Answer 1

Got a fix by specifying the item group outside the target and then using that instead.
<PropertyGroup>
<TargetsForTfmSpecificBuildOutput>$(TargetsForTfmSpecificBuildOutput);GetToolsPackageFiles</TargetsForTfmSpecificBuildOutput>
</PropertyGroup>
<ItemGroup>
<ToolDllFiles Include="$(OutputPath)\**\*.dll" />
<ToolExeFiles Include="$(OutputPath)\**\*.exe" />
</ItemGroup>
<Target Name="GetToolsPackageFiles">
<ItemGroup>
<BuildOutputInPackage Include="#(ToolDllFiles)">
<TargetPath>$([MSBuild]::MakeRelative('$(OutputPath)', %(ToolDllFiles.FullPath)))</TargetPath>
</BuildOutputInPackage>
<BuildOutputInPackage Include="#(ToolExeFiles)">
<TargetPath>$([MSBuild]::MakeRelative('$(OutputPath)', %(ToolExeFiles.FullPath)))</TargetPath>
</BuildOutputInPackage>
</ItemGroup>
</Target>