[BUG] Panic on call "parse_args_or_exit()"

[qwerty19106]

I build this code as binary file.

extern crate argparse;

use argparse::{ArgumentParser, Store, StoreTrue};

fn main() -> std::io::Result<()> {
    let mut write_filename = String::new();
    let mut tty_device = String::new();

    {
        let mut ap = ArgumentParser::new();
        ap.refer(&mut tty_device)
            .add_option(&[], Store, "tty device")
            .required();
        ap.parse_args_or_exit();
    }

    Ok(())
}

I called my_bin and got panic:

./target/debug/my_bin
thread 'main' panicked at 'index out of bounds: the len is 0 but the index is 0', /home/pc/.cargo/registry/src/github.202132.xyz-1ecc6299db9ec823/argparse-0.2.1/src/parser.rs:517:40
note: Run with `RUST_BACKTRACE=1` for a backtrace.
Process exited with code 101.

I think the problem is contained on this line:

.add_option(&[], Store, "tty device")

[tailhook]

Option is expected to contain non-zero options (first argument). what we can do, is turning it into a more helpful panic in .add_option(...) call instead of parse_args_or_exit()

PRs are welcome