It seems your variant does not support the common convention to use lone two dashes ('--') to separate options from non-options that for some reason start with dashes too (e.g. strangely named files).
My version supports typed values at a different level integrated with config file parsing. So the command line argument values are just strings for me.
> It seems your variant does not support the common convention to use lone two dashes ('--') to separate options from non-options that for some reason start with dashes too (e.g. strangely named files).
It does, actually. See http://repo.or.cz/OptFetch.git/blob/HEAD:/optfetch.c#l172