FreeBSD 8.0-RELEASE-p2 Python 2.5.5 amd64 attached diff provides a test for cpickle which reproduces a segfault when pickling >15 nested dicts in a threaded environment cpickle.patch attached to http://bugs.python.org/issue3640 applys cleanly to the 2.5 source and fixes this issue i understand 2.5 is no longer maintained except for security fixes, i leave it up to the maintainers to decide if this segfault warrants a security patch thank you
Python has several known crashers, they are not considered as security holes. It seems that FreeBSD has a small stack size for threads (64k); did you try to increase it with thread.stack_size(10**6)?