rust/src/test/run-fail/alt-bot-fail.rs

// error-pattern:explicit failure
use std;
import std::option::*;

fn foo(s: str) { }

fn main() {
    let i = alt some::<int>(3) {
        none::<int>. { fail }
        some::<int>(_) { fail }
    };
    foo(i);
}