Logged In: YES 
user_id=158581

Tried on both GNu/Linux and NetBSD:

restart
Undefined command: "restart".  Try "help".
(gdb) show version
GNU gdb 6.3
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public
License, and you are
welcome to change it and/or 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.
This GDB was configured as "i686-pc-linux-gnu".
(gdb) info checkpoint
Undefined info command: "checkpoint".  Try "help info".