title: pip, proxy authentication and "Not supported proxy scheme"
body: <p>Trying to install pip on a new python installation. I am stuck with proxy errors. Looks like a bug in <code>get-pip</code> or <code>urllib3</code>??</p>
  
  <p>Question is do I have to go through the pain of setting up <a href="https://stackoverflow.com/questions/14149422/using-pip-behind-a-proxy">CNTLM as described here</a> or is there a shortcut?</p>
  
  <p><a href="http://pip.readthedocs.org/en/latest/installing.html" rel="noreferrer">get-pip.py documentation</a> says use <code>--proxy="[user:passwd@]proxy.server:port"</code> option to specify proxy and relevant authentication. But seems like pip passes on the whole thing as it is to <code>urllib3</code> which interprets "myusr" as the url scheme, because of the ':' I guess (?).</p>
  
  <pre><code>C:\ProgFiles\Python27&gt;get-pip.py --proxy myusr:mypswd@111.222.333.444:80
  Downloading/unpacking pip
  Cleaning up...
  Exception:
  Traceback (most recent call last):
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\basecommand.py", line 122, in main
      status = self.run(options, args)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\commands\install.py", line 278, in run
      requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\req.py", line 1177, in prepare_files
      url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\index.py", line 194, in find_requirement
      page = self._get_page(main_index_url, req)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\index.py", line 568, in _get_page
      session=self.session,
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\index.py", line 670, in get_page
      resp = session.get(url, headers={"Accept": "text/html"})
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\_vendor\requests\sessions.py", line 468, in get
      return self.request('GET', url, **kwargs)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\download.py", line 237, in request
      return super(PipSession, self).request(method, url, *args, **kwargs)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\_vendor\requests\sessions.py", line 456, in request
      resp = self.send(prep, **send_kwargs)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\_vendor\requests\sessions.py", line 559, in send
      r = adapter.send(request, **kwargs)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\_vendor\requests\adapters.py", line 305, in send
      conn = self.get_connection(request.url, proxies)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\_vendor\requests\adapters.py", line 215, in get_connection
      block=self._pool_block)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\_vendor\requests\packages\urllib3\poolmanager.py", line 258, in proxy_fro
  m_url
      return ProxyManager(proxy_url=url, **kw)
    File "c:\users\sg0219~1\appdata\local\temp\tmpxwg_en\pip.zip\pip\_vendor\requests\packages\urllib3\poolmanager.py", line 214, in __init__
      'Not supported proxy scheme %s' % self.proxy.scheme
  AssertionError: Not supported proxy scheme myusr
  
  Storing debug log for failure in C:\Users\myusr\pip\pip.log
  
  C:\ProgFiles\Python27&gt;
  </code></pre>
  
  <p>When I run the command without the usrname and password it works fine, but proxy rejects the request saying it needs authentication ("407 authenticationrequired").</p>
  
  <pre><code>C:\ProgFiles\Python27&gt;get-pip.py --proxy 111.222.333.444:80
  Downloading/unpacking pip
    Cannot fetch index base URL https://pypi.python.org/simple/
    Could not find any downloads that satisfy the requirement pip
  Cleaning up...
  No distributions at all found for pip
  Storing debug log for failure in C:\Users\sg0219898\pip\pip.log
  
  C:\ProgFiles\Python27&gt;cat C:\Users\sg0219898\pip\pip.log
  ------------------------------------------------------------
  C:\ProgFiles\Python27\get-pip.py run on 09/29/14 16:23:26
  Downloading/unpacking pip
    Getting page https://pypi.python.org/simple/pip/
    Could not fetch URL https://pypi.python.org/simple/pip/: connection error: ('Cannot connect to proxy.', error('Tunnel connection failed: 407 authenticationrequired',))
    Will skip URL https://pypi.python.org/simple/pip/ when looking for download links for pip
    Getting page https://pypi.python.org/simple/
    Could not fetch URL https://pypi.python.org/simple/: connection error: ('Cannot connect to proxy.', error('Tunnel connection failed: 407 authenticationrequired',))
    Will skip URL https://pypi.python.org/simple/ when looking for download links for pip
    Cannot fetch index base URL https://pypi.python.org/simple/
    URLs to search for versions for pip:
    * https://pypi.python.org/simple/pip/
    Getting page https://pypi.python.org/simple/pip/
    Could not fetch URL https://pypi.python.org/simple/pip/: connection error: ('Cannot connect to proxy.', error('Tunnel connection failed: 407 authenticationrequired',))
    Will skip URL https://pypi.python.org/simple/pip/ when looking for download links for pip
    Could not find any downloads that satisfy the requirement pip
  Cleaning up...
    Removing temporary dir c:\users\sg0219~1\appdata\local\temp\pip_build_SG0219898...
  No distributions at all found for pip
  Exception information:
  Traceback (most recent call last):
    File "c:\users\sg0219~1\appdata\local\temp\tmp36ynxd\pip.zip\pip\basecommand.py", line 122, in main
      status = self.run(options, args)
    File "c:\users\sg0219~1\appdata\local\temp\tmp36ynxd\pip.zip\pip\commands\install.py", line 278, in run
      requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
    File "c:\users\sg0219~1\appdata\local\temp\tmp36ynxd\pip.zip\pip\req.py", line 1177, in prepare_files
      url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
    File "c:\users\sg0219~1\appdata\local\temp\tmp36ynxd\pip.zip\pip\index.py", line 277, in find_requirement
      raise DistributionNotFound('No distributions at all found for %s' % req)
  DistributionNotFound: No distributions at all found for pip
  
  C:\ProgFiles\Python27&gt;
  </code></pre>
  
  <p>I had a brief look at <a href="https://github.com/shazow/urllib3/blob/master/urllib3/poolmanager.py" rel="noreferrer"><code>urllib3\poolmanager.py</code></a> and it doesn't seem to have anything to do with username/passwords.</p>