I am trying to debug a program, but don't have experience with gdb and
don't really know what I'm looking for! The end of the program is

fprintf(stderr,"Hello6\n");

return 0;
}

The Hello6 prints out correctly, and the program did all it was meant
to do, but then:

% gdb -c rmusers.core rmusers
GDB is free software and you are welcome to distribute copies of it
 under certain conditions; type "show copying" to see the conditions.
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.11 (i386-netbsd), Copyright 1993 Free Software Foundation, Inc...
Core was generated by `rmusers'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /usr/libexec/ld.so...done.
Reading symbols from /usr/lib/libc.so.12.17...done.
#0  0x65657267 in end ()
(gdb) bt
#0  0x65657267 in end ()
#1  0x61686320 in end ()
Cannot access memory at address 0x65642c29.
(gdb)

What should I look for? (Not that it matters that much, the thing
completed the job in hand by then.)

Cheers,

 Patrick