.NET 6 Preview - Sdk NuGet packages broken for WPF projects

[kygagner]

Issue Description

I have created a custom SDK. This SDK imports Microsoft.NET.Sdk to use its functionality and also extends the build with new functionality of its own. Whereas most projects build fine using the custom SDK, this is broken for WPF projects as of the .NET 6 preview (this worked in .NET 5). The error is as follows:

D:\GIT\sdk-test\WpfApp\WpfApp_z0ggbjqk_wpftmp.csproj(9,31): error MSB4236: The SDK 'MyCustomSdk/1.0.0' specified could not be found.

Steps to Reproduce

Consume a custom SDK as a NuGet package instead of Microsoft.NET.Sdk in a WPF project. The custom SDK should import Microsoft.NET.Sdk.

I have created a repository to demonstrate the issue easily: https://github.com/kygagner/reproduce-net6-sdk-bug
This is also attached as a .zip file. repro.zip

Versions & Configurations

• MSBuild version: 17.0.0-preview-21460-01+8f208e609
• dotnet version: 6.0.100-rc.1.21463.6
• Windows 10 version: 1909

Attach a binlog

Here is a binlog for convenience: binlog.zip

[rainersigwald]

@ryalanms, does this ring a bell for you?

[ryalanms]

The issue with SDK's that come from a PackageReference was fixed by @ThomasGoulet73 in this PR:

#5426

Until this is in, the workaround is to set IncludePackageReferencesDuringMarkupCompilation to false for SDK's that come from PackageReferences.

[kygagner]

@ryalanms verified on my small repro project, going to try on our main project now.

[kygagner]

@ryalanms yes, this workaround is OK on our main solution as well.

A note for those who may be reading this: putting <IncludePackageReferencesDuringMarkupCompilation>false</IncludePackageReferencesDuringMarkupCompilation> in your Directory.Build.props will not work. Try Directory.Build.targets instead.

[jtbrower]

To keep my repositories clean and tidy, I have set BaseOutputPath and BaseIntermediateOutputPath to a custom location for years, but the WPF tmp projects have haunted me off and on such that I have needed to make minor modifications to my build process to assure it worked again. Now that it has suddenly broken again, I see that placing IncludePackageReferencesDuringMarkupCompilation in my Build.targets file and setting it to false, works like a charm.

Although I see a plethora of PRs around the dotnet repos all pointing back to using IncludePackageReferencesDuringMarkupCompilation, I could not find any information on whether or not doing this causes other issues. One gentlemen did indicate in his PR that this "comes with its own problems", but did not state what those were.

In the context of "I just want to continue to place my build artifacts in their own directory" can anyone help me with the following questions.

1. In a WPF application with hundreds of libraries, all targeting Net6.0-windows, what "bonus features" can I expect by setting IncludePackageReferencesDuringMarkupCompilation to false?
2. Once this issue is addressed in the related Microsoft PRs, if I forget to remove IncludePackageReferencesDuringMarkupCompilation from my targets file, will I end up with broken builds again?

This is one of those headaches that has always frustrated me because changing where I want my obj/bin files to land shouldn't be this intricate. Those wpftmp projects seem to show up in places I wouldn't expect them and I am hoping to solve this once and for all. Thank you for any guidance you can offer.

[ryalanms]

Adding IDC WPF: @vishalmsft @singhashish-wpf ...