Timer not firing on WatchOS 3
<p>I'm calling <code>startTimer()</code> and getting "start timer" printed in the console, but the scheduled timer never fires. Any thoughts?</p>

<pre><code>func startTimer() {
    print("start timer")
    let timerDidFire: (Timer) -&gt; Void = { timer in
        print("timer")
        self.updateLabels()
    }

    timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true, block: timerDidFire)
}
</code></pre>