And I'll save merlyn some time by pointing out that fatalsToBrowser should be used only while testing, not in production because it gives the bad guys more information than you want to give them. :)
In the NMS programs we originally used the CGI::Carp set_message() method to conditionally output the actual error message if a $DEBUGGING variable was set - thus retaining the ability to catch fatal errors (and be able to use 'die' in the programs without getting a 500 status) and control what information that gets emitted to the user. We subsequently discovered that set_message() wasn't available in older versions of CGI::Carp so we have provided our own cut-down version.