Function find_last_path_arg_value 

fn find_last_path_arg_value<'a>(
    extra_args: &'a [String],
    name: &str,
) -> Option<&'a str>

Extracts the last valid -<name>=<path> value from Zebra’s extra args.

zcashd takes the last occurrence of a single-valued command-line option, so bootstrap and preflight must resolve duplicates the same way, or Zebra would prepare one path while zcashd starts in another.