title: Build wheel for a package (like scipy) lacking dependency declaration
body: <p>I think it doesn't make a difference here but I'm using Python 2.7.</p>
  
  <p>So the general part of my question is the following: I use a separate <code>virtualenv</code> for each of my projects. I don't have administrator access and I don't want to mess with system-installed packages anyway. Naturally, I want to use wheels to speed up package upgrades and installations across the <code>virtualenv</code>s. How can I build a wheel whose dependencies are only met within a specific <code>virtualenv</code>?</p>
  
  <p>Specifically, issuing</p>
  
  <pre><code>pip wheel -w $WHEELHOUSE scipy
  </code></pre>
  
  <p>fails with</p>
  
  <pre><code>Building wheels for collected packages: scipy
    Running setup.py bdist_wheel for scipy
    Destination directory: /home/moritz/.pip/wheelhouse
    Complete output from command /home/moritz/.virtualenvs/base/bin/python -c "import setuptools;__file__='/home/moritz/.virtualenvs/base/build/scipy/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" bdist_wheel -d /home/moritz/.pip/wheelhouse:
    Traceback (most recent call last):
  
    File "&lt;string&gt;", line 1, in &lt;module&gt;
  
    File "/home/moritz/.virtualenvs/base/build/scipy/setup.py", line 237, in &lt;module&gt;
  
      setup_package()
  
    File "/home/moritz/.virtualenvs/base/build/scipy/setup.py", line 225, 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
  Cleaning up...
  </code></pre>
  
  <p>because <code>numpy</code> is not globally present and while building the wheel works when a <code>virtualenv</code> with <code>numpy</code> installed is active, it seems like a terrible idea to have the wheel depend on a specific <code>virtualenv</code>'s version of <code>numpy</code>.</p>
  
  <p><code>pandas</code> which also depends on <code>numpy</code> appears to install its own components of <code>numpy</code> but I'm not sure that's the best solution.</p>
  
  <p>I could install <code>numpy</code> with <code>--user</code> and use that to build the <code>scipy</code> wheel. Are there better options?</p>