#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#![feature(never_type)]
#![feature(unwrap_infallible)]
fn only_bad_news() -> Result<!, String> {
    Err("Oops, it failed".into())
}
fn main() {
    let error: String = only_bad_news().into_err();
    println!("{error}");
}