Puppeteer
Emperor
When you go to download Godot the website tells you it requires either the .NET SDK or the Mono SDK and if you don't install either it can't compile anything.
It needs msbuild and maybe some of the tooling, not the CLR. I'm a bit confused about what exactly the "Godot SDK" is, too, but I know we don't import the Godot namespace, and although the SDK is gettable with nuget I have been so far unsuccessful in trying to use any of Godot from outside Godot. Not that we need to, really...I just occasionally try to figure out if using xUnit is even possible Godot Mono code.
Where are you seeing this? The log file says "Could not load file or assembly System.Text.Json [...] or one of its dependencies" which makes me think the problem is not with the JSON file itself.
I'm not getting that. I'm wondering if that has to do with whatever you mean by going back and forth between dotnet and mono.
dotnet 5 has System.Text.Json "built in" whereas in mono 472 it needs to be added as a nuget package, but that's already in the csproj file, so I am not clear on why you would be seeing those errors.
Building with Godot should be performing a `nuget restore` before building which should fetch the needed nuget packages. I guess you can try that manually. The mono and dotnet tools put their build objects in different places I think, so if you are switching back and forth you'd need to "dotnet restore" for dotnet or "nuget restore" for mono, but I think the Godot build should be doing that for you.
Maybe try hitting that "build" button instead of build project? Quintillus found that it seems to do something extra over the build project or build scene buttons.