I think that will also mess up anything which is doing an eval and then checking $@ afterwards.
I should have been more clear in my question, I'm not asking "how do I do this?", I already know how to do it. I'm asking "is this readily available already?" because it's pretty amazing that after all these years, there is no standard, easy way to force Perl to give a stacktrace when it dies.
In particular I want to be able to say to someone who's using my code and having problems, "run it again with perl -MDevel::Verbose and send me the output" and they'll be able to get it from CPAN and the code should work just as before.