post_install () { cat << EOF ==> Add this code to your .emacs file to use the mode: (require 'cider) ==> Or, with use-package: (use-package cider) ==> From the README: Simply open in Emacs a file belonging to your lein or boot project (like foo.clj) and type M-x cider-jack-in. This will start an nREPL server with all the project dependencies loaded in and CIDER will automatically connect to it. Alternatively you can use C-u M-x cider-jack-in to specify the name of a lein or boot project, without having to visit any file in it. EOF } post_upgrade () { post_install $1 }