test_enable_file, test_enable_single_thread, test_gil_released and test_read_null read an int (4 bytes) from the address 0 (NULL).

test_sigsegv pass: this test raises explicitly a SIGSEGV and the signal handler writes the right message ("Segmentation fault").

Mac OS X Lion raises maybe a SIGILL on a segmentation fault if the address is zero? I suppose that it raises a SIGSEGV if the address is not zero.

Can you try to modify the function faulthandler_read_null() in Modules/faulthandler.c: replace "int *x = NULL, y;" by "int *x = (int *)1, y;" ? Then recompile (make) and rerun the test (./python.exe -m test -v test_faulthandler).