rust/src/test/run-fail/task-spawn-barefn.rs

// error-pattern:Ensure that the child thread runs by panicking
// ignore-emscripten Needs threads.

use std::thread;

fn main() {
    // the purpose of this test is to make sure that thread::spawn()
    // works when provided with a bare function:
    let r = thread::spawn(startfn).join();
    if r.is_err() {
        panic!()
    }
}

fn startfn() {
    assert!("Ensure that the child thread runs by panicking".is_empty());
}