Lack of binding-files and bloated *.xproj update

[maciej-izak]

Description

In the case of more advanced csproj/fsproj files with <Import Project="foo.props" />, PAKET is not able to generate app.config/web.config. It happens when item TargetFrameworks from PropertyGroup is moved from main project file to some *.props file and when framework is defined in paket.dependencies file (for example framework: net48, netcoreapp3.1). I need custom props and targets files beacuse I have large set of projects with many common parts. Also my project layout is related to BaseIntermediateOutputPath problem:

dotnet/msbuild#1603

With custom props/targets files the csproj/fsproj looks much better, but the solution in above issue affects PAKET in strange way. The MSBuild is detected as MSBuild v4, and instead of simple single entry:

<Import Project=".paket\Paket.Restore.targets" />

I have such monster in my project file:

  <Choose>
    <When Condition="$(TargetFrameworkIdentifier) == '.NETFramework' And $(TargetFrameworkVersion) == 'v4.8'">
      <ItemGroup>
        <Reference Include="Newtonsoft.Json">
          <HintPath>packages\Newtonsoft.Json\lib\net45\Newtonsoft.Json.dll</HintPath>
          <Private>True</Private>
          <Paket>True</Paket>
        </Reference>
      </ItemGroup>
    </When>
    <When Condition="$(TargetFrameworkIdentifier) == '.NETCoreApp' And $(TargetFrameworkVersion) == 'v3.1'">
      <ItemGroup>
        <Reference Include="Newtonsoft.Json">
          <HintPath>packages\Newtonsoft.Json\lib\netstandard2.0\Newtonsoft.Json.dll</HintPath>
          <Private>True</Private>
          <Paket>True</Paket>
        </Reference>
      </ItemGroup>
    </When>
  </Choose>

Repro steps

Move TargetFrameworks from PropertyGroup from main project file to new *.props file and import this new *.props into main project. Add framework: net48, netcoreapp3.1 into paket.dependencies file, then try to execute dotnet paket install --create-new-binding-files.

Example project with bat script attached in zip archive: PaketTest.zip.

Expected behavior

PAKET should be able to detect TargetFrameworks in imported *.props files for proper generation of binding-files and should detect proper MSBuild version.

Actual behavior

If TargetFrameworks is moved to *.props file, generation/update of binding-files doesn't work (is simply ignored) and bloated <Choose> section is added to project.

Known workarounds

Add TargetFrameworks to main project file and live with bloated <Choose>...