Thank you (for both replies) and to everyone else, this makes it crystal clear what's going on - there's a lack of "hey everyone, this is very unstable at the moment and the basic internals are changing, using anything except the latest Github builds is highly discouraged" which might really help when added to the various places above.

I'm a toe-dipper -- I need to run and play with some sample code (basic Hello, World stuff) to see if I like the ergonomics and wish to continue looking deeper, when an article is posted on HN and piques my interest to go try out (zig) the easy route is taken - install what Arch has as the latest and just test it out with the basics. ("The learn guide says I must have 4 spaces, what if I use 2? yeah OK that still works")