.NET: warning : The file '~/.nuget/packages/fsharp.core/6.0.0/contentFiles/any/netstandard2.1/FSharp.Core.xml' does not specify a 'PublishFolderType' metadata, and a default value could not be calculated. The file will not be copied to the app bundle.

[rolfbjarne]

Repro:

• Build monotouch-test for macOS:

    cd tests/monotouch-test/dotnet/macOS
    make build
    ...
    [...]/xamarin-macios/builds/downloads/dotnet-sdk-6.0.301-[...]/packs/Microsoft.macOS.Sdk/12.3.0[...]/targets/Xamarin.Shared.Sdk.targets(1439,3): warning : The file '[...]/xamarin-macios/tests/dotnet/packages/fsharp.core/6.0.0/contentFiles/any/netstandard2.1/FSharp.Core.xml' does not specify a 'PublishFolderType' metadata, and a default value could not be calculated. The file will not be copied to the app bundle. [[...]/xamarin-macios/tests/monotouch-test/dotnet/macOS/monotouch-test.csproj]
  

Binlog: build-2022-05-09-145149.binlog.zip

The reason is that the FSharp.Core NuGet does this in its nuspec:

<contentFiles>
  <files include="**/FSharp.Core.xml" buildAction="None" copyToOutput="true" flatten="true" />
</contentFiles>

which seems to come from here: dotnet/fsharp#10579 ("Following this change, build and publish will deploy the FSharp.Core.xml doc comment file to the output directory, without the build author having to do any extra work.")

It seems this could be a workaround (untested, from dotnet/fsharp#11143 (comment))

<ItemGroup>
    <PackageReference Update="FSharp.Core" Version="5.0.1">
        <ExcludeAssets>contentFiles</ExcludeAssets>
    </PackageReference>
</ItemGroup>

An alternative solution would be to amend our logic that figures out what to do with files in ResolvedFileToPublish (https://github.com/xamarin/xamarin-macios/blob/main/dotnet/BundleContents.md), to say something like: "If an xml file matches the filename of any assembly, then treat that xml file as PublishFolderType=Assembly" - so FSharp.Core.xml would be placed next to FSharp.Core.dll (and no warning produced). The downside is that the app would ship a file it doesn't need.

See also #15897 (comment).

[mattjohnsonpint]

FYI, I have a slightly different issue with the same symptom, and was able to work around it. See dotnet/maui#7272 (comment)

[jwosty]

Potentially related to fsprojects/Paket#4149