Quicklisp is a start, and I like that it's a Debian-style distribution because it can at least move towards making the assertion that everything in the distribution is mutually compatible. The problem is that the underlying ecosystem has no culture of saying "version X of library A is only compatible with versions Y+ of library B". You can put that info in the asdf system definition but I don't see many examples of it.

The other problem is rate of updates, and that's a symptom of it basically being on one person's shoulders to keep it ticking over. I can't readily think of another major language ecosystem with that characteristic. It just seems really fragmented.