title: iPhone - debugging "pointer being freed was not allocated" errors
body: <p>When over freeing a pointer you may see an error such as</p>
  
  <p>"pointer being freed was not allocated"</p>
  
  <p>When debugging with the simulator, I add a build argument MallocStackLogging = YES - this allows me to use malloc_history in the terminal to track down where I have over freed a pointer.</p>
  
  <p>If I debug on the device with this build argument I get all sorts of console errors "cannot create stack log files" etc.</p>
  
  <p>Oddly, I get some over freed pointer errors appearing on the device, but not on the simulator.</p>
  
  <p>Has anyone had any experience tracking these down using the device itself?</p>
  
  <p>Thanks!</p>