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### Unhandled SIGSEGV in Sage 6.8

I am trying to use python multiprocessing to start worker threads that execute a complex algorithm and produce rows of a matrix. Along the way, worker threads attempt to row reduce the rows they have produced using the echelonize() method.

This works in some cases. However, when working with a 9 x 860 matrix over QQ, the worker thread crashes with

------------------------------------------------------------------------
Unhandled SIGSEGV: A segmentation fault occurred in Sage.
This probably occurred because a *compiled* component of Sage has a bug
in it and is not properly wrapped with sig_on(), sig_off().
Sage will now terminate.
------------------------------------------------------------------------


If I comment out the echelonize() call, the crash does not happen.

I pickled the matrix and loaded into an interactive sage session and echelonize() succeeded.

Any suggestions for how to debug this situation are appreciated.

Vince