I'm running unittests on a CentOS 6.4 Virtual Box slave via Jenkins on a 
Windows host. Randomly I get core dumps for no obvious reason. I don't
use any C extension in my code and don't use ctypes. The (proprietary)
software is plain Python with a multi-threaded architecture.

There might be a threading race condition in the code but according
to http://stackoverflow.com/a/13654489/851737 this shouldn't result
in a segfault. So it might be a bug in Python.

I appended one log (I have various others if you wish to see them) with 
faulthandler enabled by https://pypi.python.org/pypi/nose-faulthandler.