(fn [a-b a_b] (fn [] a_b a-b))
throws
CompilerException java.lang.ClassFormatError: Duplicate field name&signature
This is caused due to how clojure munges `-` as simply `_` – another way to trigger a similar error is:
Fixing this would require changing the name munging scheme clojure has been using for the past 10 years, which could have some severe unexpected consequences, not sure how viable that would be