I created in the python module gsl_fft a __del__ method to release 
workspace when the data size changes.  It is called upon exiting 
python, and gave errors without traceback.  So I registered it with 
atexit.  This caused core dump.  The attached tape archive has 
necessary modules, and file gdb.output.  The latter contains, I hope, 
enough information to reconstruct the command line and even to find 
the cause.  Additionally you'll need the gsl and gslcblas shared 
object libraries.