Maybe it would be helpful to index the source code you have, in such a way that you can see where all the sub definitions really are -- in other words, something along the lines of "grep -n sub_name *.pl" (assuming all the source code files for this set of object modules is in the current directory), but more comprehensive than that. There is a simple-minded first attempt here, which might at least be suggestive. You could probably adapt this sort of approach by flagging the cases of "sub sub_name {...}" that happen to contain "SUPER::sub_name", so as to eliminate all the false alarms.

(A real stack trace would of course be very useful as well, giving information that this sort of index cannot provide, but -- sorry -- I haven't had much exposure to that issue.)