title: Encountering error when installing rpy2: Tried to guess R's HOME but no R command in the PATH
body: <p>I've seen a lot of posts here and elsewhere about this error, but none of the proposed solutions appear to be relevant. I'm on <a href="https://stackoverflow.com/questions/20202757/tried-to-guess-rs-home-but-no-r-command-in-the-path-osx-10-6">Python 2.7.9</a>, I have <a href="https://stackoverflow.com/questions/29741232/error-tried-to-guess-rs-home-but-no-r-command-in-the-path">an R executable in my path</a>, and I'm trying to install it on an RHEL server not on Windows. </p>
  
  <p>Here's the specific error I'm seeing. Does anybody have any idea what would be causing it or how to fix it? Thanks!</p>
  
  <pre><code>$ pip install rpy2
  Downloading/unpacking rpy2
    Downloading rpy2-2.5.6.tar.gz (165kB): 165kB downloaded
    Running setup.py (path:/tmp/pip_build_my520/rpy2/setup.py) egg_info for package rpy2
      Error: Tried to guess R's HOME but no R command in the PATH.
      Complete output from command python setup.py egg_info:
      Error: Tried to guess R's HOME but no R command in the PATH.
  </code></pre>