[Distutils] pkg_resource require does not seem to find my egg

[Nicholas Veeser]

I am working on a tool we call dino which uses sqlalchemy 0.5.3
Its an update of a previous version (called dino) which uses sqlalchemy 
0.4.4.

For reasons I don't have to go into, I would like to have both tools 
installed on the same host,
with almost no changes to the existing tool.   Thus both versions of 
sqlalchemy installed

So my solution seemed to be use pkg_resources and egg's:

- leave sqlalchemy 0.4.4 in:
    /usr/lib64/python2.4/site-packages/sqlalchemy
- build sqlalchemy 0.5.3 as an Egg and install into:
    /usr/lib64/python2.4/site-packages/SQLAlchemy-0.5.3-py2.4.egg
- in the root package of the new code,  specify the correct version
    from pkg_resources import require; require("SQLAlchemy>=0.5.0")


This does not work.
It does not seem to find the egg, and only finds the old version, and 
then (correctly) fails.

Trying to read through the pkg_resource.py, I am trying to make sense 
why this is, and
how to get around it.  I am having trouble wrapping my head around some 
of the terms...


Am I doing something obviously wrong?
Is there a known bug?
I have installed setuptools-0.6_rc7

Here is the traceback
Traceback (most recent call last):
  File "/usr/bin/dinoadm", line 8, in ?
    import dino.cmd.cli
  File "/usr/lib64/python2.4/site-packages/dino/__init__.py", line 6, in ?
    require("SQLAlchemy>=0.5.0")
  File "/usr/lib64/python2.4/site-packages/pkg_resources.py", line 626, 
in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib64/python2.4/site-packages/pkg_resources.py", line 528, 
in resolve
    raise VersionConflict(dist,req) # XXX put more info here
pkg_resources.VersionConflict: (SQLAlchemy 0.4.4 
(/usr/lib64/python2.4/site-packages), 
Requirement.parse('SQLAlchemy>=0.5.0'))



Thanx
Nicholas