FYI - I’ve created a simple way to run nREPL 0.4 (https://github.com/nrepl/lein-nrepl)
Updating cider-nrepl to target nREPL 0.4+ is in progress https://github.com/clojure-emacs/cider-nrepl/pull/540
I ran into some mysterious problem with this, so I’d appreciate some help with debugging! 🙂