Enabling SkiaRenderer gives build error for browserwasm target when using CSharpMarkup.WinUI.Uno.Extensions.* NuGets

[VincentH-Net]

With C# Markup 3.1.0, When I use SkiaRenderer in a Uno.Sdk 6.0.67 project with net9.0-browserwasm target when that project references a NuGet that was itself built with the same Uno Sdk version (against net8.0-browserwasm amongst others - it is https://www.nuget.org/packages/CSharpMarkup.WinUI.Uno.Extensions.Navigation/3.1.0), I get below build error for the browserwasm target:

Unable to Uno.WinUI.Runtime.Skia.WebAssembly.Browser and Uno.UI.WebAssembly cannot be used at the same time."

[jeromelaban]

@VincentH-Net I'm not reproducing this error, could you post a repro sample?

[VincentH-Net]

@jeromelaban here is a minimal repro; sln with only a presentation library project with wasm target:
Csm2Issue45Repro.zip

Rebuild (vs 17.13.6 using .NET SDK 9.0.203) gives error:

C:\Users\dev\.nuget\packages\uno.winui.runtime.webassembly\6.0.465\buildTransitive\Uno.WinUI.Runtime.WebAssembly.targets(14,3): error : Unable to Uno.WinUI.Runtime.Skia.WebAssembly.Browser and Uno.UI.WebAssembly cannot be used at the same time.

Observations:

• Once you get this error you need to close and reopen VS to retest - it sticks.
• When you exclude the example code and comment out the CSharpMarkup.WinUI.Uno.Extensions.* package references, retest gives build succeed.
• The other CSharpMarkup.WinUI NuGets do not have this issue. The difference is that the CSharpMarkup.WinUI.Uno.Extensions.* packages use Uno.Sdk - they mimic the underlying Uno packages that also do this, e.g.
  • https://github.com/unoplatform/uno.extensions/blob/main/src/Uno.Extensions.Navigation.UI/Uno.Extensions.Navigation.WinUI.csproj
  • plus https://github.com/unoplatform/uno.extensions/blob/main/src/Directory.Build.props (this contains the __RemoveUnoRuntimeWasm target that I tried to copy in both my NuGet projects and the Presentation project - without effect)

Thanks for looking into this!

[VincentH-Net]

@jeromelaban Basically what I am looking for is a way to build a NuGet that depends on a Uno Extensions NuGet where both use Uno.Sdk.
Even when I added the __RemoveUnoRuntimeWasm to my NuGet, the resulting assembly for browserwasm referenced Uno.UI.Runtime.WebAssembly, while the Uno NuGet does not:

[jeromelaban]

Thanks for the repro.

This behavior is expected, albeit a bit difficult to explain. We tried here, but it may not be enough.

In your case, because the library provides browserwasm, it will generate a version of the dependency tree that explicitly depends on wasm native rendering.

To fix your problem, you should not be adding both desktop and browserwasm targets in your library. When an app will reference you library, it will fallback automatically to net8.0 which is compatible with all Skia targets.

That way, your library will stay compatible with both native and skia based renderers.

[VincentH-Net]

Thanks for the direction - I removed both desktop1.0 and browserwasm1.0 targets from the C# Markup 2 companion NuGets for the Uno.Extensions.* NuGets, and kept the net8.0 target. It all works now with both Native and Skia renderers.

@jeromelaban One question: I verified that the generated C# Markup 2 code for the desktop1.0, browserwasm1.0 and net8.0 targets of the Uno.Extensions.* NuGets is identical, in other words:

The API's exposed in the Uno.Extensions.* NuGets for the desktop1.0, browserwasm1.0 and net8.0 targets are identical

However, are these API's guaranteed to stay identical across these targets, or is that just the current state of the Uno.Extensions.* NuGets?