panic!("alive call line {}: {:?}", line, alive);

        if !alive.is_empty() {
            panic!("alive call line {}: {:?}", line, alive);
        } else {
            panic!("reachable: {:?}", reachable);
        }

        debug!(
            "Deleting {:?} {:?} {:?} {:?}",
            a, b, p.introduced_by, p.flag
        );

            debug!("repair down");

        } else if !p.flag.is_folder() {

        } else if b_is_alive && !p.flag.is_folder() {
            debug!("repair up");