Python segfault on Mac OS X 10.7

mutex.c

#include <pthread.h>

pthread_mutex_t mutex;

// compile and link with: cc -c mutex.c; ld -dylib -o libmutex.dylib mutex.o -lpthread

segfault.py

import ctypes
import ctypes.util

mutex = ctypes.cdll.LoadLibrary('./libmutex.dylib')
pthread = ctypes.cdll.LoadLibrary(ctypes.util.find_library('pthread'))
pthread.pthread_mutex_init(ctypes.byref(mutex.mutex), None)

# segfaults from python gc on exit