Note: help and version output are generated by a naïve script which tries a few variants of
<command> --help, <command> -h etc. to find the command's help and version info.
Sometimes it gets lucky, sometimes it doesn't; if the output below looks wrong, it probably is.
grodvi --version (return code: 0)
GNU grodvi (groff) version 1.22.3
grodvi --help (return code: 0)
usage: grodvi [-dv] [-F dir] [-w n] [files ...]