Pip installations of Bob packages installs each package several times

In a clean environment without any bob package installed the pip install bob command will install each package several times which makes it impractical to install. While this was done to circumvent the problem described here: https://stackoverflow.com/questions/14665936/import-egg-functionality-during-setup-in-a-buildout I think this approach should have been avoided. a great example is Scipy which depends on Numpy during build. Looking at Scipy's setup.py I see that they have managed this pretty well: https://github.com/scipy/scipy/blob/master/setup.py