When developing in Clojure I use reloaded.repl to regularly reset the REPL state.

However, if you’ve just switched to a new git branch and files that were present on the previous branch are no longer present then a (reset) will throw a java.io.FileNotFoundException.

To fix this we need to reset the list of files that clojure.tools.namespace is tracking:

(alter-var-root #'clojure.tools.namespace.repl/refresh-tracker 
  (fn [_ ] (clojure.tools.namespace.track/tracker)))
(reloaded.repl/reset)

I’ve set up a keybinding for this in my editor and use it each time I want to reset the REPL state.