Comment 0 for bug 659231

To reproduce:

sudo apt-get install zope.interface
bzr lp:mailman
cd mailman
(edit buildout.cfg to remove the include-site-packages line)
python bootstrap.py
bin/buildout

Here's the problem. I have python-zope.interface package installed on Ubuntu 10.10. Mailman requires zope.interface and several other zope.* packages, like .component, .configuration, and .testing. When I buildout the tree I get errors that 'zope' has no module 'interface', and I think the reason is that namespace packages aren't set up correctly between the builtout environment and the system's packages.

Specifically, I can see that those other zope packages get downloaded (the once that aren't installed in site), and when I import zope from bin/py I can see the namespace package, but it apparently cannot find zope.interface, which is in dist-packages. Suppressing include-site-packages "fixes" the problem in that zope.interface in dist-packages is ignored and it's downloaded into my buildout environment.