Launch pdb on runtime exceptions -- put this in site-packages/sitecustomize.py or somesuch.

sitecustomize.py

# auto stop in pdb on noneexceptions
def info(exc_type, value, tb):
 # dont do anything for keyboard interrupts or exit signals
 if exc_type in (KeyboardInterrupt, SystemExit):
   return
 if hasattr(sys, 'ps1') or not sys.stderr.isatty():
   # we are in interactive mode or we don't have a tty-like
   # device, so we call the default hook
   sys.__excepthook__(exc_type, value, tb)
 else:
  import traceback, pdb
  # we are NOT in interactive mode, print the exception...
  traceback.print_exception(exc_type, value, tb)
  print

  # ...then start the debugger in post-mortem mode.
  pdb.pm()

sys.excepthook = info