[release/10.0.1xx] Previous SDK legs failing to resolve SDK 'Microsoft.NET.Sdk.WindowsDesktop'

[ellahathaway]

Legs building with the previous source-built SDK are failing to build roslyn with the following error:

  /__w/1/s/src/roslyn/src/EditorFeatures/CSharp/Microsoft.CodeAnalysis.CSharp.EditorFeatures.csproj : error : Could not resolve SDK "Microsoft.NET.Sdk.WindowsDesktop". Exactly one of the probing messages below indicates why we could not resolve the SDK. Investigate and resolve that message to correctly specify the SDK.
  /__w/1/s/src/roslyn/src/EditorFeatures/CSharp/Microsoft.CodeAnalysis.CSharp.EditorFeatures.csproj : error :   [UnifiedBuildSdkResolver] 0 overrides found for 'Microsoft.NET.Sdk.WindowsDesktop'
  /__w/1/s/src/roslyn/src/EditorFeatures/CSharp/Microsoft.CodeAnalysis.CSharp.EditorFeatures.csproj : error :   SDK resolver "Microsoft.DotNet.MSBuildWorkloadSdkResolver" returned null.
  /__w/1/s/src/roslyn/src/EditorFeatures/CSharp/Microsoft.CodeAnalysis.CSharp.EditorFeatures.csproj : error :   The NuGetSdkResolver did not resolve this SDK because there was no version specified in the project or global.json.
  /__w/1/s/src/roslyn/src/EditorFeatures/CSharp/Microsoft.CodeAnalysis.CSharp.EditorFeatures.csproj : error MSB4236: The SDK 'Microsoft.NET.Sdk.WindowsDesktop' specified could not be found.

Link to failure

[mthalman]

@ViktorHofer - Is this related to the windowsdesktop changes you've been working on?

[ViktorHofer]

Yes. The EmptySdk workaround needs to temporarily be brought back. Same in main.

[ellahathaway]

Resolved by dotnet/dotnet#2244