Getting control of `pdb` back from App Engine in Emacs

Question

I have a Python Google App Engine application I'd like to debug on the dev server, in Emacs. I have a pdb executable file I created so that debugging would play nice with Emacs:

$ which pdb
/usr/bin/pdb
$ cat /usr/bin/pdb
#/bin/sh
exec python -m pdb "$@"

In Emacs, I M-x pdb and get prompted Run pdb (like this): to which I enter pdb /usr/local/bin/dev_appserver.py /Users/[person]/path/to/app/directory.

This starts off nicely. I get a window with a (Pdb) prompt, I can set breakpoints successfully in early parts of the code like some of the dev_appserver.py file and use commands like n to step through line at a time. I can then enter c to continue with program execution.

Problem is, as soon as app engine has printed out its usual startup INFO messages (to the same buffer the Pdb session is taking place in), I don't get a (Pdb) prompt back again, so I can't enter any more pdb commands. This is both my first time using pdb and my first time debugging in Emacs, so maybe I'm just doing something plain wrong.

Answer 1

@TimHoffman has a good answer. The dev server re-routes pdb from the various actual server processes, so you're not going to be able to launch pdb from the command line.

An alternative which might work is to launch the dev server from your emacs command line without pdb, and insert a pdb breakpoint in your code

import pdb
pdb.set_trace()

I typically debug with this, but not via emacs.