title: Grails promises are not executed reliably
body: <p>The project uses Grails 2.3.11</p>
  
  <p>This code should print exactly 100 lines:</p>
  
  <pre><code>(0..99).each { i -&gt;
    Promises.task {
      println("i = $i")
    }
  }
  </code></pre>
  
  <p>But this doesn't happen.
  I see different number of printed lines every time.
  Seems like some promises are eaten.</p>
  
  <p>Why does this happen?</p>