title: Django South Seg Fault
body: <p>I just updated from Ubuntu 12.04 to 13.04, and I am having issues migrating some code that used to work.  Googling does not reveal anything that obviously looks related except some obscure R references, and though my project does use R I would not expect it to crop up in migrations.  I have never dealt with debugging seg faults before, much less in 3rd party code.  How should I proceed?</p>
  
  <pre><code>(project)ben@Watt:~/Projects/project/project$ python project/manage.py migrate
  Error: 'rho' must be an environment not NULL: detected in C-level eval
  Segmentation fault (core dumped)
  </code></pre>
  
  <p>EDIT: It looks like a problem with rpy2, found using the ltrace from the answer below.  Still wondering how that came up in migrate.</p>
  
  <p>EDIT2: My R version had been updated beyond what Rpy2 likes.  Reverting fixed things.  How this came up in ./manage.py migrate is mysterious to me.</p>