Not sure what or when this changed, but there is now an error message at the bottom of my dev ZenMagick site:

‘Fatal error: Exception thrown without a stack frame in Unknown on line 0′

It seems to happen within the exit statement, so after some research I think it is related to error handler or shutdown handler code. Hmmm….

EDIT: Turns out that it is a bad idea to call parent::__destruct(); if that method doesn’t exist…