Standard: Trimming fails for .NET Framework projects that use PackageReference

[jnm2]

The csproj has:

  <PropertyGroup>
    <TrimUnusedDependencies>true</TrimUnusedDependencies>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="SourceLink.Embed.AllSourceFiles" Version="2.7.4" PrivateAssets="all" />
    <PackageReference Include="Microsoft.Packaging.Tools.Trimming" Version="1.1.0-preview1-25818-01" />
  </ItemGroup>

It fails to build, giving:

Microsoft.Packaging.Tools.Trimming.targets(55,5): error MSB4018: The "TrimFiles" task failed unexpectedly.
System.Exception: Root package SourceLink.Embed.AllSourceFiles was specified but was not found in PackageDependencies
at Microsoft.DotNet.Build.Tasks.TrimFiles.GetPackageRoots(IDictionary`2 packages, Trimmable trimmable)
at Microsoft.DotNet.Build.Tasks.TrimFiles.Execute()
at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
at Microsoft.Build.BackEnd.TaskBuilder.d__26.MoveNext()

Is this expected to work?

[jnm2]

When I remove PrivateAssets="all", a separate PackageReference starts causing the same error even though it does not have PrivateAssets specified.

[jnm2]

Would repro projects help?

[ericstj]

I see what's happening. Updated the title of the bug and will put together a fix.

[ericstj]

Actually, hold up I may have spoken too soon. Which version of the SDK are you using? It's possible that this change went through and I need to react to it: https://github.com/dotnet/standard/issues/626

[jnm2]

This is a .NET Framework project building in the Visual Studio 15.6.1 IDE. That makes sense.

[ericstj]

Got it. Reproducing now. The bug is due to missing the PackageDependency item completely in old NuGet targets, so similar to #626 but for a different reason. To workaround it you can set

  <PropertyGroup>
    <RootPackageReference>false</RootPackageReference>
  </PropertyGroup>

This will turn of our package graph rooting completely, but you'll still get the binary graph rooting. I'll need to bring back lock/asstets file reading to get the package graph for this and #626.

[jnm2]

Great! I was looking for something like <RootPackageReference>false</RootPackageReference> earlier but didn't dig into the targets. Think a quick list of the interesting properties and items could be documented?

[ericstj]

We have that here: https://github.com/dotnet/standard/blob/master/Microsoft.Packaging.Tools.Trimming/docs/trimming.md#additional-options though it could probably use some clean up (just reviewing now I see a number of typos). I'll make sure to give that some love when I address this issue as well.

[jnm2]

Silly of me, I think I saw that before and missed the significance of RootPackageReference. It's already useful. Thanks!

[ericstj]

Fixed with #671

[jnm2]

@ericstj Very cool! Is there something I can subscribe to in order to know when a new prerelease is published?

[ericstj]

Should be here: https://dotnet.myget.org/feed/dotnet-core/package/nuget/Microsoft.Packaging.Tools.Trimming. It builds daily, but I requested another build today since I missed this morning's sync point.

[ericstj]

Package is available: 1.1.0-preview1-26312-02

[godefroi]

@ericstj The latest version available from NuGet is 1.1.0-preview1-25818-01 which still has this issue. Can we get a newer version into NuGet?

[ericstj]

Yes I will publish an update.

[godefroi]

Thanks!

[ericstj]

It is published now

[godefroi]

Thanks, that version solved the issue for me. I appreciate the help.