Using `lein cljsbuild auto` should enable you to see problems in your clojurescript code as soon as you save it, and using the browser's js console enables you

Using `lein cljsbuild auto` should enable you to see problems in your clojurescript code as soon as you save it, and using the browser's js console enables you to see problems in the compiled/generated js. The stack trace printed out in case of an exception is usually informative enough. I experienced its helpfulness quite recently during my study of OP's example.