A rewrite of debugger is underway, so please try that instead. This new debugger is the way of the future.
pydb is an expanded version of the Python debugger loosely based on the gdb command set and the stock Python debugger. It also has all of the features found in an earlier version of pydb.py that was distributed with the debugger GUI ddd.
We also have a couple of cool debuggers for GNU Bash, ksh, zsh, and GNU Make.