Обрабатывает ли pip extras_requires из источников setuptools / distribute?

I have package "A" with a setup.py and an extras_requires line like:

extras_require = {
    'ssh':  ['paramiko'],
},

And a package "B" that depends on util:

install_requires = ['A[ssh]']

If I run python setup.py install on package B, which uses setuptools.command.easy_install under the hood, the extras_requires is correctly resolved, and paramiko is installed.

However, if I run pip /path/to/B or pip hxxp://.../b-version.tar.gz, package A is installed, but paramiko is not.

Because pip "installs from source", I'm not quite sure why this isn't working. It should be invoking the setup.py of B, then resolving & installing dependencies of both B and A.

Is this possible with pip?