import os

fn execute_in_thread(id int) !string {
    res := os.execute('printf thread_${id}')
    if res.exit_code != 0 {
        return error('thread ${id} failed: exit=${res.exit_code} output="${res.output.trim_space()}"')
    }
    return res.output
}

fn test_execute_inside_spawned_threads() {
    $if windows {
        return
    }
    $if macos {
        // On macos-14 GitHub Actions runners, when the V repo is checked out
        // under a path that contains non-ASCII bytes (the space-paths CI does
        // this with `你好 my $path, @с интервали`), os.execute() inside spawned
        // threads consistently returns empty output here, even with FD_CLOEXEC
        // and a V-level pthread mutex serializing pipe()+posix_spawn. Regular
        // macos CI (ASCII paths) passes the test, so skip only when the cwd
        // contains non-ASCII bytes.
        cwd := os.getwd()
        for b in cwd.bytes() {
            if b >= 0x80 {
                return
            }
        }
    }
    for _ in 0 .. 3 {
        mut threads := []thread !string{}
        for i in 0 .. 4 {
            threads << spawn execute_in_thread(i)
        }
        mut outputs := []string{cap: 4}
        for t in threads {
            outputs << t.wait() or { panic(err) }
        }
        assert outputs == ['thread_0', 'thread_1', 'thread_2', 'thread_3']
    }
}