I give myself a second account on a machine (username zaxo) who maintains a private perl installation in the home directory. If ~/bin is first in $PATH, then, zaxo runs his own perl. It is always compiled with -DDEBUGGING, and is usually somewhere near the bleading edge.

I've wished for what you want, but only when I was unprepared to deal with trouble. It's possible to fire up a script under gdb and debug at C and asm level, but that also requires that symbol tables retain names and such. That means -DDBUGGING again. Debugging perl scripts with gdb is like taking landscape photos with a microscope.