If you need the absolute most recent release of a language to write code in it, that in my opinion is a bad sign -- maybe it's still a bit new and evolving rapidly, if there's a runtime component it might be awkward to distribute to machines you want to run on, and setting the dev environment up becomes a little painful which can discourage others from contributing. Not a dealbreaker, especially if you're just experimenting or doing a small private project, but for anything serious I would be worried if I couldn't develop and run it with whatever version of a language is shipped with the major Linux distros.