Happy to help with this, just finishing up a few things I have on my plate. Should be able to get to it later today or tomorrow.

Hmm, I wonder if this can be a change purely in src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.RuntimeIdentifierInference.targets. The idea would be that we would use the SDK RID if UseCurrentRuntimeIdentifier is true or RuntimeIdentifer is unset and SelfContained is set to true.

Isn't this just the switch --use-current-runtime? I don't think we'd want to make this implicit but would rather prefer customers specify the switch.

@marcpopMSFT I think that's a question for @richlander, as that contradicts the issue description. I think the reason to set this by default is because that's effectively what we do for FX-dependent apps via the apphost. Why require extra properties for self-contained apps than FX-dependent?

Hi @agocke, is there any more changes needed, or should wait for more feedback.
cc: @richlander @marcpopMSFT

I could not run all the tests on my side, for some failed tests in Microsoft.NET.Build.Tasks.UnitTests, it would fail even when I revert my changes, could you please help me with the failed test cases.

I tested the SDK with my test project locally, seemed to work fine, the test output is as follows:

PS C:\projects\source\dotnet\sdk> dotnet publish -c Release --self-contained C:\projects\test\DynamicStaticFileProvider
Microsoft (R) Build Engine version 17.0.0-preview-21411-06+b0bb46ab8 for .NET
Copyright (C) Microsoft Corporation. All rights reserved.

  Determining projects to restore...
  Restored C:\projects\test\DynamicStaticFileProvider\DynamicStaticFileProvider.csproj (in 9.19 sec).
  You are using a preview version of .NET. See: https://aka.ms/dotnet-core-preview
  DynamicStaticFileProvider -> C:\projects\test\DynamicStaticFileProvider\bin\Release\net5.0\win-x64\DynamicStaticFileProvider.dll
  DynamicStaticFileProvider -> C:\projects\test\DynamicStaticFileProvider\bin\Release\net5.0\win-x64\publish\

and the project file had not defined the RID, the project file content is as follows:

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net5.0</TargetFramework>
  </PropertyGroup>
</Project>