How to set Swift version 5 (for recent dev snapshots) in Xcode build settings?

Thank you!

Just out of curiosity, what environment are people using for eg trying out Swift 5?

I get the feeling I'm the only one trying to use Xcode for this, and everyone else is using some much better setup, how else to explain the fact that this thread seems to be the only place on the internet that talks about this problem?

Or is almost no one trying out Swift 5 (on larger projects, with code completion, etc)?