"pip install xxx --download yyy --no-deps" runs "python setup.py egg_info" after downloading (to generate the requires.txt dependency list?). This seems unnecessary.

This is a problem in the case of "cryptography", since its setup.py uses setup_requires, which automatically downloads its dependencies at the slightest nudge, even just --help (cryptography issue #716).

This impedes using pip install --download to build a collection of trusted (checksummed) modules for later installation.