This code fails an assertion

selecti_fail.rs

use pipes::*;
use task::spawn;

fn main() {
    let (p1, c1) = pipes::stream();
    let (p2, c2) = pipes::stream();

    do spawn {
        for int::range(1, 7) |i| {
            c1.send(i);
        }
    }

    do spawn {
        for 3.times {
            c2.send(true);
        }
    }

    let mut ports = ~[p1.header(), p2.header()];

    loop {
        match selecti(ports) {
            0 => {
                match p1.try_recv() {
                    Some(n) => error!("Number: %?", n),
                    None => break,
                }
            }
            1 => {
                match p1.try_recv() {
                    Some(b) => error!("Bool: %?", b),
                    None => break,
                }
            }
            _ => fail,
        }
    }
}