ResolvePackageAssets target is skipped for multiple target frameworks and Rebuild target in 17.2.0

Issue Description

The ResolvePackageAssets target is skipped if three conditions are met:

1. The feature “multiple target frameworks” is used in csproj;
2. The Rebuild target is selected;
3. The version of msbuild is 17.2.0 or newer.

That results in skipping code generation from source-only nuget packages with pp-files. That results in failed rebuilds.

The Build target runs the ResolvePackageAssets target in such conditions. Also, some older versions of the msbuild run the ResolvePackageAssets target is such conditions.

Steps to Reproduce

1. Create an ClassLibrary1.csproj file in an empty folder with the following content:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFrameworks>netstandard2.0</TargetFrameworks>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="StackTraceParser.Source" Version="1.3.1" />
  </ItemGroup>
</Project>

1. Add an cs-file to the folder:

namespace ClassLibrary1
{
    public class GeneratedFileContainer
    {
        StackTraceParser x;
    }
}

1. Run dotnet build /t:rebuild in the folder.

Expected Behavior

Build succeeded.

Actual Behavior

Build FAILED.

d:\work\CheckNullaRebuild\ClassLibrary1\GeneratedFileContainer.cs(5,9): error CS0246: The type or namespace name ‘StackTraceParser’ could not be found (are you missing a using directive or an assembly reference?)

Analysis

dotnet build /t:build finishes successfully. So there is an issue the Rebuilt target.

The type StackTraceParser is generated by the ResolvePackageAssets target from pp-file. See https://github.com/atifaziz/StackTraceParser/blob/master/StackTraceParser.csproj#L66

The reason why the ResolvePackageAssets target is skipped during the Rebuild target run is value of the _CleaningWithoutRebuilding parameter. In order for the target to be run, the parameter should not have a true value.

If the selected target is Build, the _CleaningWithoutRebuilding parameter is undefined. So the ResolvePackageAssets target is not skipped.

If the feature “multiple target frameworks” is not used in csproj and the selected target is Rebuild, the _CleaningWithoutRebuilding parameter is set to true by the _SdkBeforeClean target and then set to false by the_SdkBeforeRebuild target. So the ResolvePackageAssets target is not skipped.

If the feature “multiple target frameworks” is used in csproj and the selected target is Rebuild, the _CleaningWithoutRebuilding parameter is set to true by the _SdkBeforeClean target. But it is never set to false because the DispatchToInnerBuilds runs the Build target instead of the Rebuild target for each target framework. So the _CleaningWithoutRebuilding parameter value remains true and the ResolvePackageAssets target is not run.

Versions & Configurations

d:\work\CheckNullaRebuild\ClassLibrary1>dotnet msbuild --version
Microsoft (R) Build Engine version 17.2.0+41abc5629 for .NET
Copyright (C) Microsoft Corporation. All rights reserved.

17.2.0.20702

[Forgind]

Great repro, by the way, @alexandersorokin. Very helpful in pointing me to the underlying issue.

[benvillalobos]

MSBuild Team Triage: The targets for this issue don’t exist in the msbuild repo. The flags that control the build ordering seem to exist in the SDK repo: _SdkBeforeRebuild _SdkBeforeClean , etc. Moving to the sdk repo