round-trip from egg to code and back to egg

[Catherine]

I'd like to use Scriptaculous with TurboGears on Python 2.5.
Unfortunately, Scriptaculous is currently in the Cheese Shop only as a
Python 2.4 egg.

If I had the setup.py that was used to generate the egg, I think it
would be really easy to generate a new Python 2.5 egg from the
existing 2.4 egg.  In fact, it would be gruntwork we could easily
offload from the package authors.

The trouble is, an egg doesn't include setup.py.  Is there any direct
way to round-trip a Python package from egg to installed code and into
a new egg?  I might be able to mine enough information from the files
in EGG-INFO to reconstruct setup.py - reverse-engineering - but that
seems unnervingly like work.

Three possibilities come to mind -

1. I'm missing something simple
2. setuptools could be modified to include the original setup.py with
the egg
3. a script could mine EGG-INFO to regenerate setup.py - maybe such a
script has already been written?

Can somebody who understands eggs better comment?

Thanks very much!
- Catherine
http://catherinedevlin.blogspot.com