(gdb) bt
#0  0x009eb7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
#1  0x00a2b7f5 in raise () from /lib/tls/libc.so.6
#2  0x00a2d199 in abort () from /lib/tls/libc.so.6
#3  0x00a5f4ea in __libc_message () from /lib/tls/libc.so.6
#4  0x00a65c6f in _int_free () from /lib/tls/libc.so.6
#5  0x00a65fea in free () from /lib/tls/libc.so.6
#6  0x080615af in ast_channel_free (chan=0x99a5388) at channel.c:953
#7  0x080681bd in ast_hangup (chan=0x99a5388) at channel.c:1386
#8  0x00648be2 in do_parking_thread (ignore=0x0) at res_features.c:1610
#9  0x00bca371 in start_thread () from /lib/tls/libpthread.so.0
#10 0x00acb9be in clone () from /lib/tls/libc.so.6
(gdb) bt full
#0  0x009eb7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
No symbol table info available.
#1  0x00a2b7f5 in raise () from /lib/tls/libc.so.6
No symbol table info available.
#2  0x00a2d199 in abort () from /lib/tls/libc.so.6
No symbol table info available.
#3  0x00a5f4ea in __libc_message () from /lib/tls/libc.so.6
No symbol table info available.
#4  0x00a65c6f in _int_free () from /lib/tls/libc.so.6
No symbol table info available.
#5  0x00a65fea in free () from /lib/tls/libc.so.6
No symbol table info available.
#6  0x080615af in ast_channel_free (chan=0x99a5388) at channel.c:953
        cur = Variable "cur" is not available.
(gdb)