I think this case is a bit different than the one above. This multimethod default will only be hit if an unrecognized or invalidly formatted selector is used when calling `with-handler`. Slingshot handles this kind of thing like so:  https://github.com/scgilardi/slingshot/blob/master/src/slingshot/support.clj#L161

I think it might be a good idea to do likewise, but I'm not sure how to format the exception. Would it be a dire exception? Should we try to re-create the slingshot exception? In essence, it ought to be the slightshot exception, since we ought to be deferring to their (currently unexposed) catch logic to handle matching their selector syntax. Whatever kind of exception gets raised here, it'll build a back-compat issue into dire; you wouldn't want to change the exception carelessly once it's released since people may build code around it. If slingshot ever does expose the catch clause logic, would dire need to then update the exception thrown in this case?

I didn't have good answers to those questions, so I did what any good dev would do and punted. :laughing:   Suggestions welcomed.