C#: Fallback to the latest SDK

[raulsntos]

When trying to find the .NET SDK, we were using MSBuildLocator.RegisterDefaults as a fallback assuming it was picking the latest one. That's not correct, it uses the first one it finds (see microsoft/MSBuildLocator#81).

• The new implementation picks the latest version so it should fix Generating the C# project fails when .Net 8 Sdk is installed. #81133. But I don't have a Windows machine to test this.

[akien-mga]

Thanks!

[jasonswearingen]

EDIT: setting the env var DOTNET_ROLL_FORWARD_TO_PRERELEASE to 1 and now it builds/runs properly.

Original Message:

@raulsntos dotnet8rc2 does not seem to work with godot 4.2 beta3 (on Win11x64).
I set my C# .csproj target framework to:
<TargetFramework>net8.0</TargetFramework>

It looks like the C# project builds fine (both via Visual Studio and Godot's build) but when running via the godot editor the following error occurs:

modules/mono/mono_gd/gd_mono.cpp:538 - .NET: Failed to load project assembly. (User)
modules/mono/mono_gd/gd_mono.cpp:538 - .NET: Failed to load project assembly. (User)
modules/mono/mono_gd/gd_mono.cpp:538 - .NET: Failed to load project assembly. (User)
modules/mono/mono_gd/gd_mono.cpp:512 - .NET: Giving up on assembly reloading. Please restart the editor if unloading was failing. (User)

No additional info is given when I set The Godot Editor's setting DotNet->build-> verbosity to "Diagnostic"

sorry I am not familiar with godot's build/engine internals, but If you want me to help test fixes for the next beta, let me know