After a rash of changes, I started getting segfaults in my Catalyst application. Of course, they didn't happen when I ran under perl -d alone, and oddly enough, it didn't happen when I was logged into the app either, which seems like some sort of interaction between my use/disuse of Storable for authenticated users.
Once I finally found the right module, and one perl -d:Trace later the culprit was: Clone::clone. Upgrading from 0.23 to 0.27 fixed the problem.
Devel::Trace + + for pinpointing the line of code right before el crasho out of all the crap between me and Catalyst.