为什么pip在虚拟环境中不起作用？

Question

I am trying to use pip from virtual enviroment on Linux Ubuntu 14.04 x64.

While using pip from shell as:

pip search bla

it works fine.

But using from virtualenv it shows error:

(proj_testing)uxu@box:~$ pip search bla
/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
Exception:
Traceback (most recent call last):
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/basecommand.py", line 223, in main
    status = self.run(options, args)
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/commands/search.py", line 43, in run
    pypi_hits = self.search(query, options)
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/commands/search.py", line 60, in search
    hits = pypi.search({'name': query, 'summary': query}, 'or')
  File "/usr/lib/python2.7/xmlrpclib.py", line 1233, in __call__
    return self.__send(self.__name, args)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1587, in __request
    verbose=self.__verbose
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/download.py", line 785, in request
    headers=headers, stream=True)
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/_vendor/requests/sessions.py", line 508, in post
    return self.request('POST', url, data=data, json=json, **kwargs)
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/download.py", line 373, in request
    return super(PipSession, self).request(method, url, *args, **kwargs)
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/_vendor/requests/sessions.py", line 465, in request
    resp = self.send(prep, **send_kwargs)
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/_vendor/requests/sessions.py", line 573, in send
    r = adapter.send(request, **kwargs)
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/_vendor/cachecontrol/adapter.py", line 46, in send
    resp = super(CacheControlAdapter, self).send(request, **kw)
  File "/home/uxu/.virtualenvs/proj_testing/local/lib/python2.7/site-packages/pip/_vendor/requests/adapters.py", line 431, in send
    raise SSLError(e, request=request)
SSLError: [Errno 1] _ssl.c:510: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed

It doesn't make sense, anyone got idea?

Answer 1

Try execute pip search bla like superuser

For ubuntu the command is:

sudo pip search bla

Answer 2

From https://urllib3.readthedocs.org/en/latest/security.html :

Certain Python platforms (specifically, versions of Python earlier than 2.7.9) have restrictions in their ssl module that limit the configuration that urllib3 can apply. In particular, this can cause HTTPS requests that would succeed on more featureful platforms to fail, and can cause certain security features to be unavailable. If you encounter this warning, it is strongly recommended you upgrade to a newer Python version, or that you use pyOpenSSL as described in the OpenSSL / PyOpenSSL section.

You probably have a less recent version of python in your virtual environment. Perhaps this is why this error only occurs in the virtual environment.