From there, and for other errors, generally I use print debugging. Often times you can also just test a function in isolation on the REPL. This and the fact that you can hot-load code into a running process make print debugging tolerable.
There are fancier debugging tools in development for clojure, though I have no experience with them. Essentially they let you attach a REPL at arbitrary failure points. This would make it quite easy to identify the source of the problem.
Knowledge of the JVM does come up, but you won't be digging through compiled bytecode or the guts of java libraries (unless you use a lot of java library interop).
Debugging tends to be more REPL based than debugger based. It is possible to debug from Eclipse using the build in debugger, but it's not something i have done as it is not really necessary.