title: Make virtualenv inherit specific packages from your global site-packages
body: <p>I'm looking for a way to make a virtualenv which will contain just some libraries (which I chose) of the base python installation.</p>
  <p>To be more concrete, I'm trying to import my matplotlib to virtualenv during the creation of virtualenv. It can't be installed efficiently with pip or easy_install since it misses some fortran compiler libs. The way I did it until now was to manually copy from:</p>
  <pre><code>/usr/lib/python2.7/dist-packages/ to virtualenv_name/lib/python2.7/dist-packages/
  </code></pre>
  <p>However this prevents the manully imported links to be registerd by yolk (which prints all currently available libs in virtualenv).</p>
  <p>So, is there a way to do a selective variant of the</p>
  <pre><code>virtualenv --system-site-packages
  </code></pre>