As I understand it, this feature exists to allow you to try and figure out where and why your program is running out of memory, and maybe do some emergency cleanup. Perl will die() when it fails to malloc, but the die can be caught by a DIE signal handler which can print a stack trace. It's not very fashionable to use DIE handlers these days because of the tricky issues around using them with eval{} blocks, but it seems like you could get it to work if you really needed it.