title: Python pip install requires server_hostname
body: <p>I finished installing pip on linux, the <code>pip list</code> command works. But when using the <code>pip install</code> command it got the following error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/basecommand.py", line 232, in main
      status = self.run(options, args)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/commands/install.py", line 339, in run
      requirement_set.prepare_files(finder)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/req/req_set.py", line 333, in prepare_files
      upgrade=self.upgrade,
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/index.py", line 305, in find_requirement
      page = self._get_page(main_index_url, req)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/index.py", line 783, in _get_page
      return HTMLPage.get_page(link, req, session=self.session)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/index.py", line 872, in get_page
      "Cache-Control": "max-age=600",
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/sessions.py", line 473, in get
      return self.request('GET', url, **kwargs)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/download.py", line 365, in request
      return super(PipSession, self).request(method, url, *args, **kwargs)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/sessions.py", line 461, in request
      resp = self.send(prep, **send_kwargs)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/sessions.py", line 573, in send
      r = adapter.send(request, **kwargs)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/cachecontrol/adapter.py", line 43, in send
      resp = super(CacheControlAdapter, self).send(request, **kw)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/adapters.py", line 370, in send
      timeout=timeout
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/packages/urllib3/connectionpool.py", line 518, in urlopen
      body=body, headers=headers)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/packages/urllib3/connectionpool.py", line 322, in _make_request
      self._validate_conn(conn)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/packages/urllib3/connectionpool.py", line 727, in _validate_conn
      conn.connect()
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/packages/urllib3/connection.py", line 238, in connect
      ssl_version=resolved_ssl_version)
    File "/usr/local/lib/python2.7/site-packages/pip-6.0.7-py2.7.egg/pip/_vendor/requests/packages/urllib3/util/ssl_.py", line 254, in ssl_wrap_socket
      return context.wrap_socket(sock)
    File "/usr/local/lib/python2.7/ssl.py", line 350, in wrap_socket
      _context=self)
    File "/usr/local/lib/python2.7/ssl.py", line 537, in __init__
      raise ValueError("check_hostname requires server_hostname")
  ValueError: check_hostname requires server_hostname
  </code></pre>
  
  <p>How can I fix this?</p>