loop runs.
</p>
<p>When &rsquo;proc&rsquo; executes, &rsquo;await&rsquo; and &rsquo;resume&rsquo; will still be in use by
this procedure, so they may not be reused by &rsquo;proc&rsquo; (even though
&rsquo;proc&rsquo; runs in the event loop thread).
</p>
<p>Exceptions may propagate out of this procedure if they arise while
setting up (that is, before the task starts), which shouldn&rsquo;t happen
unless memory is exhausted.  Exceptions arising during execution of
the generator, if not caught locally, will p