Presently a significant amount of packages in PyPI do not even install properly. They fail mainly due to missing files in the tarball. For example, one packages fails at "import ez_setup" because ez_setup.py was not distributed in the tarball. Some other packages fail due to missing README.txt that is used to set the long_description in setup.py (open('README.txt').read()).
I suggest that we implement a
sdist_check command that would do a check on the generated a sdist using virtualenv (if installed). Packages authors can then use it before uploading their untested, low-quality tarballs to PyPI.
If required, I can dig into the PyPM build logs and provide more details about the failing packages.