virtualenv macosX --no-site-package ignored

I'm having problems with macOSX and virtualenv. It seems to ignore --no-site-package. Using exactly the same commands with linux (archlinux) it works. It it macOSX 10.5 with python 2.5

curl -o virtualenv.py 'http://bitbucket.org/ianb/virtualenv/raw/tip/virtualenv.py

Create a new environment

python virtualenv.py --no-site-packages foo
New python executable in foo/bin/python
Installing setuptools...........................done.

Activate it

source foo/bin/activate

Try to install something in it. Despite virtualenv it looks for the system-wide install

easy_install cherrypy
Searching for cherrypy
Best match: CherryPy 3.1.2
Adding CherryPy 3.1.2 to easy-install.pth file

Using /Library/Python/2.5/site-packages
Processing dependencies for cherrypy
Finished processing dependencies for cherrypy

Yet it doesn't find the module

(foo)guidage-multimodal:~ tristram$ python
Python 2.5.1 (r251:54863, Feb  6 2009, 19:02:12) 
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import cherrypy
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named cherrypy

I tried PI开发者_开发技巧P after looking at virtualenv --no-site-packages and pip still finding global packages? However it fails installing psycopg2 (some problems with gcc). Also I would like to be able to have a setup.py (from distribute) that does the whole woork

update On macOS 10.6 it works as it is supposed to work. Maybe is python 2.5 to old, or the install is broken, so I give up and will require macOS 10.6...

It also could be that the easy_install version was too old. I'd suggest using pip:

easy_install pip
pip install virtualenv -U
virtualenv env
source env/bin/activate
pip -E env install cherrypy