n wants to know when a task fails (or finishes), and then continue with some other code. Alternatively, it might be desirable to try again a number of times before
really giving up.
</p>
<p>Janet has the concept of supervisor channels to support this. When a new task is scheduled with <code class="mendoza-code">ev/go</code>, one can optional specify a channel to set as the new tasks supervisor.
When the task yields to the event loop, or raises any kind of fiber signal, a message is automatically written to 