title: Python pip fails but packages are installed
body: <p>I'm trying to install <code>scipy</code> in a Python <a href="https://github.com/pypa/virtualenv" rel="nofollow">virtualenv</a>:</p>
  
  <pre><code>$ virtualenv venv
  New python executable in venv/bin/python
  Installing setuptools, pip, wheel...done.
  $ source venv/bin/activate
  (venv)$ pip install scipy
  Collecting scipy
    Using cached scipy-0.16.1.tar.gz
  Collecting numpy&gt;=1.6.2 (from scipy)
  /home/kramer65/zommel/venv/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
  Building wheels for collected packages: scipy
    Running setup.py bdist_wheel for scipy
    Complete output from command /home/kramer65/zommel/venv/bin/python -c "import setuptools;__file__='/tmp/pip-build-6oiqvO/scipy/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" bdist_wheel -d /tmp/tmpdmYP0Hpip-wheel-:
    Traceback (most recent call last):
      File "&lt;string&gt;", line 1, in &lt;module&gt;
      File "/tmp/pip-build-6oiqvO/scipy/setup.py", line 253, in &lt;module&gt;
        setup_package()
      File "/tmp/pip-build-6oiqvO/scipy/setup.py", line 241, in setup_package
        from numpy.distutils.core import setup
    ImportError: No module named numpy.distutils.core
  
    ----------------------------------------
    Failed building wheel for scipy
  Failed to build scipy
  Installing collected packages: numpy, scipy
    Running setup.py install for scipy
  Successfully installed numpy-1.10.1 scipy-0.16.1
  /home/kramer65/zommel/venv/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
  </code></pre>
  
  <p>This output first says <code>Failed to build scipy</code> after which it says <code>Successfully installed numpy-1.10.1 scipy-0.16.1</code>, which I don't understand.</p>
  
  <p>Does anybody know why it fails and succeeds at the same time?</p>