title: virtualenv: cannot import name 'main'
body: <p>I'm having a little trouble with virtualenv on Mac OS X Yosemite. After I couldn't run virtualenv at all first, I installed Python 3 via <code>brew</code> (previously I installed it via the package on python.org). I linked this installation of python3, updated pip and ran <code>pip3 install virtualenv</code>. When I try to run virtualenv (e.g. <code>$ virtualenv --python=python3 ../virtualenv</code>), I get the following error message.</p>
  
  <pre><code>Traceback (most recent call last):
    File "/usr/local/bin/virtualenv", line 7, in &lt;module&gt;
      from virtualenv import main
    File "/usr/local/bin/virtualenv.py", line 7, in &lt;module&gt;
      from virtualenv import main
  ImportError: cannot import name 'main'
  </code></pre>
  
  <p>Can anybody help me with this?</p>