title: Installing rpy2 on python 2.7 on macOS
body: <p>I have python version 2.7.10 on macOS High Sierra and would like to install rpy2.</p>
  
  <p>When I do <i>sudo pip install rpy2</i></p>
  
  <p>I get the error message:</p>
  
  <pre><code>Command "python setup.py egg_info" failed with error code 1 in /private/tmp/pip-build-Nwbha3/rpy2/
  </code></pre>
  
  <p>I have already upgraded setuptools (version 39.0.1). </p>
  
  <p>I also downloaded the older version rpy2-2.7.0.tar.gz and tried installing it with <i>sudo pip install rpy2-2.7.0.tar.gz</i>. I then get the following error message:</p>
  
  <pre><code>clang: error: unsupported option '-fopenmp'
  clang: error: unsupported option '-fopenmp'
  error: command 'cc' failed with exit status 1
  ----------------------------------------
  Command "/usr/bin/python -u -c "import setuptools, tokenize;__file__='/private/tmp/pip-O0cu4E-build/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-haDUA3-record/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /private/tmp/pip-O0cu4E-build/
  </code></pre>
  
  <p>If somebody has the answer to my installation problem, it would be greatly appreciate it.
  Many thanks in advance!</p>