Try getting Figwheel to work with Emacs CIDER and Spacemacs. It's a joke. This is what you have to go through: https://github.com/bhauman/lein-figwheel/wiki/Using-the-Figw... and at the end of it Spacemacs told me cider-connect-clojurescript was not available. I'm not the only one who's given up on this. Quite a few luminaries in the Clojurescript world have abandoned Emacs/CIDER.

Configuring lein scripts. Debugging JVM problems. Guess how JavaScript developers hate JVM exceptions.

Lein is a declarative build tool. Perhaps your problem lies with not understanding how the tools work?

JVM exceptions, I hated.