ruthgracewong@dev-ruthgracewong:~$ pex --disable-cache --no-pypi -f <https://pypirepo.pinadmin.com> <https://pypi-mirror.pinadmin.com/simple/> -vvvvvvvvvvv "Flask-OAuthlib==0.9.3" "auth-client==0.2.3"
Traceback (most recent call last):erpreter :: Setting up interpreter /usr/bin/python2.7
  File "/usr/local/bin/pex", line 11, in <module>
    sys.exit(main())
  File "/usr/local/lib/python2.7/dist-packages/pex/bin/pex.py", line 578, in main
    pex_builder = build_pex(reqs, options, resolver_options_builder)
  File "/usr/local/lib/python2.7/dist-packages/pex/bin/pex.py", line 504, in build_pex
    resolvables = [Resolvable.get(arg, resolver_option_builder) for arg in args]
  File "/usr/local/lib/python2.7/dist-packages/pex/resolvable.py", line 71, in get
    raise cls.InvalidRequirement('Unknown requirement type: %s' % resolvable_string)
pex.resolvable.InvalidRequirement: Unknown requirement type: <https://pypi-mirror.pinadmin.com/simple/>