<pre>0x0000000800c5be02 in _malloc_thread_cleanup () from
(gdb) bt
#0  0x0000000800c5be02 in _malloc_thread_cleanup () from
#1  0x0000000800c5d54c in _malloc_prefork () from
#2  0x0000000800c5d7cf in free () from
#3  0x0000000000411cb9 in diff_cmd () at diffcmd_.c:288
#4  0x000000000041c48e in main (argc=1, argv=0x7fffffffe710) at main_.c:261
</pre>