Through the power of a very aggressive code-edit script i managed to inject enough print statements i found a couple of spots in my application that would, under certain (not clearly known) circumstances, throw errors during DESTROY.

Basically, perl would DESTROY a IO::Socket::* instance, then call DESTROY on the instance that was using that socket and would try to cleanly close the connection. This would fail and raise an exception (not eval'ed) during DESTROY which would utterly confuse Perl 5.30.1 and/or the still-alive parts of my application (don't know which yet) which would result in an infinite loop.

I fixed that by enclosing those function calls in eval(). At least i hope that fixed it permanenty.

Unfortunately, one of those was in my Net::Clacks client, so everyone gets to enjoy adding another item to upgrade on their already too long list...