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

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

fn foo(str s) { }

fn main() {
    auto i =
        alt (some[int](3)) {
            case (none[int]) { fail }
            case (some[int](_)) { fail }
        };
    foo(i);
}