It depends on the name of the package pip could not install

[f1se4]

There are some pure python packages that are not insalled because 'due to an EnvironmentError', could it be because the size of the egg directory for these packages? There are some interesting vim plugins that are not working because python installations. For example pep8 module.

[anjiro]

I ran into the same thing and discovered that if I did cd $TMPDIR; mkdir pip-req-tracker-onn_0423 (that pip dir being listed in the EnvironmentError message), the package would install.