Restoring nuget packages does not work on Mac any more

With the latest commits on master, restoring nuget packages does not work any more in VS for Mac. I get the following errors:

/usr/local/share/dotnet/sdk/5.0.202/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.FrameworkReferenceResolution.targets(63,5): error NETSDK1100: Windows is required to build Windows desktop applications. [/Users/janus/github/Mapsui/Mapsui.Rendering.Xaml/Mapsui.Rendering.Xaml.csproj]
/usr/local/share/dotnet/sdk/5.0.202/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.FrameworkReferenceResolution.targets(63,5): error NETSDK1100: Windows is required to build Windows desktop applications. [/Users/janus/github/Mapsui/Mapsui.UI.Wpf/Mapsui.UI.Wpf.csproj]
/usr/local/share/dotnet/sdk/5.0.202/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.FrameworkReferenceResolution.targets(63,5): error NETSDK1100: Windows is required to build Windows desktop applications. [/Users/janus/github/Mapsui/Samples/Mapsui.Samples.Wpf.Editing/Mapsui.Samples.Wpf.Editing.csproj]
/usr/local/share/dotnet/sdk/5.0.202/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.FrameworkReferenceResolution.targets(63,5): error NETSDK1100: Windows is required to build Windows desktop applications. [/Users/janus/github/Mapsui/Samples/Mapsui.Samples.Wpf/Mapsui.Samples.Wpf.csproj]

I think this is happening since a99ae93a830b39f7abe0dad8f62e1a8feb2491b8, and it’s preventing me from building Mapsui on MacOS.

See also https://github.com/dotnet/sdk/issues/3803 and https://github.com/dotnet/sdk/issues/3592.

Any suggestions on how to fix it?

[janusw]

What exactly is Mapsui.iOS.sln?

Trying to answer that myself: It’s unfortunately not documented, but from the name and content it seems like this is a solution that contains everything needed to build iOS-related stuff.

Btw: Mapsui.iOS.sln is not affected by the errors mentioned above, since it does not include the corresponding projects.

In principle it would be nice if a second solution file would not be necessary at all, and until recently it actually was not really needed AFAICS. Due to the errors above it became necessary again. But IMHO it falls short of the requirements.

In general there are target platforms that can only be built on Windows (UWP/WPF), ones that can only be built on Mac (iOS/MacOS) and those that can be built on both (e.g. Android and generic libs).

Mapsui.iOS.sln falls short in the sense that it only includes the iOS-specific stuff, but misses some of the Android (and Desktop) parts. What we’d need rather than a Mapsui.iOS.sln would be a Mapsui.Mac.sln, which should include everything that could be built on Mac.

@pauldendulk If you agree, I’ll throw a PR at this problem that extends and renames Mapsui.iOS.sln.

[janusw]

I created it because the last time I tried it was not possible to build Mapsui.sln on Mac, but that was a long time ago. (It would be better if VS just ignored the files it can not build so we could work with one project).

Yes, UWP projects are ignored/disabled in VS4Mac without any problems. The same should be done for WPF stuff. To my understanding the NETSDK1100 errors above are a bug, and there are at least two related issues in dotnet (see above).

I created it for my own purpose, just building iOS, I never did serious development on Mac, so I just needed the iOS projects.

I pretty much only do development on MacOS, mostly because I’m targeting both iOS and Android, and also I kinda dislike Windows 😉

Unfortunately one often gets the impression that all the build tooling for .NET is still pretty Windows-centric, and Mac is a bit of a stepchild (not to speak of Linux).

Including the Android projects for Mac developers is good idea. I will merge the PR.

Thanks a lot 👍