title: GLIBC_2.12 Issue
body: <p>Over the past year or so, I have been encountering a problem when trying to add either GDAL or Iris on top of the Anaconda distribution. I receive the error message:</p>
  
  <pre><code>from PyQt4 import QtCore, QtGui
  ImportError                               
  Traceback (most recent call last)
  &lt;ipython-input-1-5a7197379ef6&gt; in &lt;module&gt;()
  ----&gt; 1 from PyQt4 import QtCore, QtGui
  
  ImportError: /lib64/libpthread.so.0: version `GLIBC_2.12' not found (required by /usr/local/other/SSSO_Ana-PyD/4.3.1_py2.7_gcc-5.3-sp3/lib/python2.7/site-packages/PyQt4/../../.././libglib-2.0.so.0)
  </code></pre>
  
  <p>I have a similar problem with PyQt5. I am wondering is someone has a clue on how to resolve the issue.</p>
  
  <p>I am working on a 64-bit Linux system and I have been having the problem with Anaconda 4.2.0 (and any newer version).</p>
  
  <p>Any pointer will be appreciated. Thank you in advance.</p>