為什么pip在虛擬環境中不起作用？

Question

我正在嘗試從Linux Ubuntu 14.04 x64上的虛擬環境使用pip。

使用shell的pip時：

pip search bla

它工作正常。

但是從virtualenv使用它會顯示錯誤：

(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

沒道理，有人知道嗎？

Answer 1

嘗試像superuser一樣執行pip search bla

對於ubuntu，命令為：

sudo pip search bla

Answer 2

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

某些Python平台（特別是2.7.9之前的Python版本）在其ssl模塊中具有限制，這些限制限制了urllib3可以應用的配置。 特別是，這可能會導致在功能更強大的平台上成功的HTTPS請求失敗，並可能導致某些安全功能不可用。 如果遇到此警告，強烈建議您升級到更新的Python版本，或按照OpenSSL / PyOpenSSL部分中的說明使用pyOpenSSL。

您的虛擬環境中可能裝有較新的python版本。 也許這就是為什么此錯誤僅在虛擬環境中發生的原因。