[root@inode test2]# rpm -q rpm
rpm-4.4.2.3-0.2.rc1.x86_64
[root@inode test2]# rpm --foobar
Segmentation fault (core dumped)
[root@inode test2]# rpm -Q
Segmentation fault (core dumped)

Testing on an x86 box did not yield the same result.

I don't have all the debuginfo installed, but:

Core was generated by `rpm --foobar'.
Program terminated with signal 11, Segmentation fault.
#0  0x00000031c2682480 in strlen () from /lib64/libc.so.6
(gdb) bt
#0  0x00000031c2682480 in strlen () from /lib64/libc.so.6
#1  0x00000031c264b166 in vfprintf () from /lib64/libc.so.6
#2  0x00000031c264c460 in buffered_vfprintf () from /lib64/libc.so.6
#3  0x00000031c2647886 in vfprintf () from /lib64/libc.so.6
#4  0x00000031c26fbf12 in __fprintf_chk () from /lib64/libc.so.6
#5  0x0000000000404b32 in main (argc=2, argv=<value optimized out>) at
/usr/include/bits/stdio2.h:98
#6  0x00000031c261e36a in __libc_start_main () from /lib64/libc.so.6
#7  0x0000000000403489 in _start ()
(gdb)