title: Command python setup.py egg_info failed with error code 1 Mac OS
body: <p>i know there is some poste like that but i try so mutch solutions and they don't work... 
  So i wanna build <a href="https://github.com/daid/Cura" rel="noreferrer">https://github.com/daid/Cura</a> on MAC OS X, but it's don't works, my problem is:</p>
  
  <p>When i try to did that on my virtualenv:</p>
  
  <pre><code>$ pip install -r requirements_darwin.txt
  </code></pre>
  
  <p>At the end he give me an error :</p>
  
  <pre><code>$ Command python setup.py egg_info failed with error code 1 in /Users/...
  </code></pre>
  
  <p>Any ideas ?</p>