In the newest #babashka (1.0.167) you can do this without having a fork of clojure.spec in your bb.edn:
$ bb -e "(require '[clojure.spec.alpha :as s]) (s/valid? int? 2)"
true
The source of https://github.com/babashka/spec.alpha is pre-bundled with added only 100kb to the image.
#clojure
1/2
@worldsendless If your directory has a bb.edn, you can select cider-jack-in + babashka. Or you can start the nrepl from the command line (bb nrepl-server) and then cider-connect