Roslyn projects failing to build in source-build bootstrap build

[dseefeld]

When building roslyn in a bootstrapped source-build scenario (i.e. building with a version of the SDK that has been previously source-built), any projects with <Project Sdk="Microsoft.NET.Sdk.WindowsDesktop"> fail to build. These are failing because source-build does not build the WindowsDesktop SDK. These projects are attempting to be excluded using <ExcludeFromSourceBuild>, but this fails because the project still needs to be loaded to access the property. These projects will need to be excluded using a different method for source-build. In the interim, a patch has been created including a .slnf file which excludes these projects.

src/EditorFeatures/CSharpTest2/Microsoft.CodeAnalysis.CSharp.EditorFeatures2.UnitTests.csproj
src/EditorFeatures/TestUtilities/Microsoft.CodeAnalysis.EditorFeatures.Test.Utilities.csproj
src/Interactive/Host/Microsoft.CodeAnalysis.InteractiveHost.csproj
src/Interactive/HostProcess/InteractiveHost32.csproj
src/VisualStudio/Core/Def/Microsoft.VisualStudio.LanguageServices.csproj
src/VisualStudio/Core/Impl/Microsoft.VisualStudio.LanguageServices.Implementation.csproj
src/VisualStudio/CSharp/Impl/Microsoft.VisualStudio.LanguageServices.CSharp.csproj
src/VisualStudio/CSharp/Test/Microsoft.VisualStudio.LanguageServices.CSharp.UnitTests.csproj
src/EditorFeatures/Test/Microsoft.CodeAnalysis.EditorFeatures.UnitTests.csproj
src/EditorFeatures/CSharpTest/Microsoft.CodeAnalysis.CSharp.EditorFeatures.UnitTests.csproj
src/VisualStudio/VisualStudioDiagnosticsToolWindow/Roslyn.VisualStudio.DiagnosticsWindow.csproj
src/Test/Diagnostics/Roslyn.Hosting.Diagnostics.csproj
src/VisualStudio/IntegrationTest/TestUtilities/Microsoft.VisualStudio.IntegrationTest.Utilities.csproj
src/Workspaces/CoreTestUtilities/Microsoft.CodeAnalysis.Workspaces.Test.Utilities.csproj
src/EditorFeatures/Core.Wpf/Microsoft.CodeAnalysis.EditorFeatures.Wpf.csproj
src/Interactive/HostProcess/InteractiveHost64.csproj
src/Workspaces/DesktopTest/Microsoft.CodeAnalysis.Workspaces.Desktop.UnitTests.csproj
src/EditorFeatures/DiagnosticsTestUtilities/Microsoft.CodeAnalysis.EditorFeatures.DiagnosticsTests.Utilities.csproj
src/EditorFeatures/VisualBasicTest/Microsoft.CodeAnalysis.VisualBasic.EditorFeatures.UnitTests.vbproj
src/EditorFeatures/Test2/Microsoft.CodeAnalysis.EditorFeatures2.UnitTests.vbproj
src/VisualStudio/VisualBasic/Impl/Microsoft.VisualStudio.LanguageServices.VisualBasic.vbproj
src/VisualStudio/Core/Test/Microsoft.VisualStudio.LanguageServices.UnitTests.vbproj
src/VisualStudio/TestUtilities2/Microsoft.VisualStudio.LanguageServices.Test.Utilities2.vbproj
src/EditorFeatures/TestUtilities2/Microsoft.CodeAnalysis.EditorFeatures.Test.Utilities2.vbproj

[dagood]

Here's the PR adding the patch that does this: dotnet/installer#12500.