title: why doesn't this work in XCode debug window "po [myNsDateComponent weekday]"
body: <p>why doesn't this work in XCode debug window "po [myNsDateComponent weekday]" ?</p>
  
  <p>Specific example:</p>
  
  <pre><code>(gdb) po weEndDayTime
  &lt;NSDateComponents: 0x4f241d0&gt;
  
  (gdb) po [weEndDayTime weekday]
  0x2 does not appear to point to a valid object.
  </code></pre>