Ulrich Drepper <drepper(a)cygnus.com&gt; writes in xemacs-beta(a)xemacs.org: ... That's a very likely possibility. I was not suggesting it was, nor was I referring at all to your implementation, but rather to how I've seen XEmacs behave when it is about to go down in flames. XEmacs does quite a lot when a fatal error occurs and it is not uncommon that a second fatal error occurs when it is trying to clean up from the first one. In general I want to aim towards simplifying the fatal error code because as you point out, no matter how carefully you code, you can still be defeated if your memory gets clobbered.