``` (gdb) f 1 #1 t_unref (p_msg=<optimized out>) at t_lookup.c:1515 1515 t_lookup.c: No such file or directory. (gdb) print T $1 = (struct cell *) 0x0 ```
``` (gdb) f 2 #2 t_unref (p_msg=<optimized out>) at t_lookup.c:1484 1484 in t_lookup.c (gdb) print T $2 = (struct cell *) 0x0 ```