How to get setuptools to use a relative path in easy-install.pth when doing "setup.py develop"

I'm installing a python egg using setup开发者_如何转开发tools with the "python setup.py develop" command. It's important that all install paths be relative. I see that I can do:

python setup.py develop --egg-path ../../../../my_directory

and the .egg-link file uses that relative path. However, the path added to easy-install.pth still is an absolute path. How do I make the path in the easy-install.pth file a relative path?

If your sourcecode is in a subdirectory of the installation directory, it will be made relative automatically.

Why do you need it to be relative, anyway?