py3 setup.py monkeypatch breaks setup.py develop for other 2to3-relying packages
On Python 3.2, currently when someone issues the following commands, they'll wind up with a completely uninformative setuptools error:
$ mkdir tmp $ cd tmp $ virtualenv3.2 env $ env/bin/easy_install pyramid $ env/bin/pcreate -s alchemy alch $ virtualenv3.2 env2 $ cd alch $ ../env2/bin/python setup.py develop
The error comes from setuptools/sandbox.py and provides no traceback object.
If the user reruns the "setup.py develop" step, the installation completes.
This happens because SQLAlchemy monkeypatches 2to3 and doesn't un-monkey-patch it. When another 2to3-using package tries to invoke 2to3 to run fixers (in the same process space), it fails.
Note that this is only true of "setup.py develop", not of "easy_install" for whatever reason.
A patch is attached which undoes the monkeypatch after SQLALchemy runs "run_setup()".