Function parse_push_recurse_submodules_arg 

pub fn parse_push_recurse_submodules_arg(
    opt: &str,
    arg: &str,
) -> Result<PushRecurseSubmodules, String>

Parse --recurse-submodules=<value> or push.recurseSubmodules / submodule.recurse.

Returns an error for invalid values (yes, unknown strings, etc.).