title: Spark - Lost task in stage
body: <p>Any ideas why this would not work?</p>
  
  <pre><code>val m = sc.union(sc.parallelize(0 until 10).map(n =&gt; sc.parallelize(n until 20))).collect()
  </code></pre>
  
  <p>I know there are other ways to do this, but I'm more interested in why it does not work.</p>
  
  <p>results: <a href="http://pastebin.com/FuiKFMMA" rel="nofollow">http://pastebin.com/FuiKFMMA</a></p>