I don't know if someone might be using [an older git](https://github.com/keplerproject/luarocks/issues/106). Also instead of adding these & those options, wouldn't it be better to pass a list with command line options down to git, e.g list(branch="xyz", recursive=TRUE) or as a single string. I'm not sure though whether it would work fine on *nix if all arguments are lumped into a single string. And for the former example, something needs to be done to convert `recursive=TRUE` into just `--recusrive`.