title: rpy2 complaining with undefined symbol: Rf_translateCharUTF8
body: <p>I built R and rpy2 following the steps <a href="https://stackoverflow.com/a/14824147/283296">here</a>, and when I test <code>import rpy2.tests</code> I get the following error:</p>
  
  <p><code>/path/to/python2.7/site-packages/rpy2/rinterface/_rinterface.so: undefined symbol: Rf_translateCharUTF8</code></p>
  
  <p>in an exception thrown by <code>rpy2.interface._rinterface import *</code></p>
  
  <p>Any thoughts why?</p>