as per "grub-mkconfig -h" "grub-mkconfig -v" should print version but it does not but its takes upper case of "v".
root@heartbeat:~# grub-mkconfig -v
Unrecognized option `-v'
Usage: grub-mkconfig [OPTION]
Generate a grub config file
-o, --output=FILE output generated config to FILE [default=stdout]
-h, --help print this message and exit
-v, --version print the version information and exit
Report bugs to <
bug-grub@gnu.org>.