title: How to detect the object being double released with Xcode - message sent to deallocated instance?
body: <p>I am relatively new to Xcode4 and I would like to know how can I identify a double release with it. </p>
  
  <p>In the debugger I see a line like <code>*** -[NSConcreteMutableData release]: message sent to deallocated instance 0x60b63fe0</code>.</p>
  
  <p>The problem is that knowing the address doesn't help a lot identifying the object and also the object type doesn't help too much identifying it.</p>
  
  <p>I read <a href="http://www.friday.com/bbum/2010/01/10/using-malloc-to-debug-memory-misuse-in-cocoa/" rel="nofollow">http://www.friday.com/bbum/2010/01/10/using-malloc-to-debug-memory-misuse-in-cocoa/</a> but I did not found this to be too successful.</p>