In my system (MacOS Ventura on Apple M1 + brew) Babashka's output is not printed. Thus, bb -f script.clj just silently returns the prompt, and not the value of the last expression in the script.
I figured eventually that I needed to add another option bb --prn -f script.clj works fine. Maybe some system-wide default settings somewhere causes this.
The reason why I'm reporting it, as this is in the first chapter and for making the key argument about the coolness of babashka.