rust "loan...conflicts with prior loan" errors

hashmap-borrow.rs

use core::hashmap::HashMap;

fn main() {
    let mut map : HashMap<~str, int> = HashMap::new();
    let keys = ~[~"foo", ~"bar", ~"foo"];
    do keys.consume |_, key| {
        let count;
        {
            let count_option = map.find(&key);
            match count_option {
                Some(x) => { count = *x; },
                None => { count = 0; }
            }
        }
        map.insert(key, count + 1); 
    }

    for map.each |&key, &count| {
        println(fmt!("%?: %?", key, count));
    }
}

Now I get a "task ... ran out of stack" error when I run the compiled program.
rustc is
rustc 0.6 (ee3789b 2013-04-24 13:33:29 -0700)
that I just built from incoming.