How do I remedy "The "Copy" task does not support copying directories" in azure-devops build step?

Question

From what I've gathered, the only change made since the last build in Azure-DevOps is the version of this nuget-package. So either there is a mistake made in there (which I am not privy to investigate) or the problem lies elsewhere in the build task.

[error]f:\WorkB_tool\dotnet\sdk\5.0.102\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Publish.targets(237,5): Error MSB3025: The source file "C:\windows\ServiceProfiles\NetworkService.nuget\packages\package\version\staticwebassets\css\open-iconic\FONT-LICENSE" is actually a directory. The "Copy" task does not support copying directories.

The error is clear enough I suppose, but I haven´t found a resource on what is causing it or how to fix it.

Answer 1

By adding a file ending (css\open-iconic\FONT-LICENSE.txt) the build could proceed. However, why this was suddenly an issue still perplexes me.

Answer 2

It seems that there is something wrong with Copy Task from your <packages_id>.props file,

Copy task should work with files rather than a folder, so you should use this:

<ItemGroup>
           <File Include="$(MSBuildThisFileDirectory)xxx\staticwebassets\assets\libs\flot-charts\Makefile\*.*"></File>
    </ItemGroup>
    
<Target Name="xxx" AfterTargets="xxx">
     <Copy SourceFiles="@(File)" DestinationFolder="xxx"></Copy>

</Target>

We could also copy the file via task copy file.