Run through the Quick Start and go down through to the Browser REPL portion (https://github.com/clojure/clojurescript/wiki/Quick-Start#browser-repl), but exclude the :watch option from repl.clj.
Then further down, where the new symbol is introduced
instead cause some duplicate symbols to be introduced in order to provoke compiler warnings:
Then evaluate the require statement in the tutorial and observe that the warnings are emitted twice:
Quick Start Browser REPL with :watch off