title: EXC_BAD_ACCESS (code=1, address=0x0) when stepping in debugger
body: <p>My application crashes each and every time I try to step over a call. Without debugger it works fine. </p>
  
  <p>Also, when I run the app in simulator it woks fine with or without debugger.</p>
  
  <p>Recently I upgraded my Mac OS X 10.8 to 10.9 (Mavericks). There were no issues before the upgrade. </p>
  
  <p>What causes the issue and how could I fix it? </p>
  
  <p>Below is the back trace. My app uses ARC. I have enabled zombies and added exception breakpoint but no zombies where detected and exception breakpoint is never triggered.</p>
  
  <pre><code>    * thread #1: tid = 0x2503, 0x00000000, queue = 'com.apple.main-thread, stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
          frame #0: 0x00000000
          frame #1: 0x35e170c4 UIKit`-[UIApplication sendAction:to:from:forEvent:] + 72
          frame #2: 0x35e17076 UIKit`-[UIApplication sendAction:toTarget:fromSender:forEvent:] + 30
          frame #3: 0x35e17054 UIKit`-[UIControl sendAction:to:forEvent:] + 44
          frame #4: 0x35e1690a UIKit`-[UIControl(Internal) _sendActionsForEvents:withEvent:] + 502
          frame #5: 0x35e16e00 UIKit`-[UIControl touchesEnded:withEvent:] + 488
          frame #6: 0x35d3f5f0 UIKit`-[UIWindow _sendTouchesForEvent:] + 524
          frame #7: 0x35d2c800 UIKit`-[UIApplication sendEvent:] + 380
          frame #8: 0x35d2c11a UIKit`_UIApplicationHandleEvent + 6154
          frame #9: 0x37a1e5a2 GraphicsServices`_PurpleEventCallback + 590
          frame #10: 0x37a1e1d2 GraphicsServices`PurpleEventCallback + 34
          frame #11: 0x33ef9172 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 34
          frame #12: 0x33ef9116 CoreFoundation`__CFRunLoopDoSource1 + 138
          frame #13: 0x33ef7f98 CoreFoundation`__CFRunLoopRun + 1384
          frame #14: 0x33e6aebc CoreFoundation`CFRunLoopRunSpecific + 356
          frame #15: 0x33e6ad48 CoreFoundation`CFRunLoopRunInMode + 104
          frame #16: 0x37a1d2ea GraphicsServices`GSEventRunModal + 74
          frame #17: 0x35d80300 UIKit`UIApplicationMain + 1120
          frame #18: 0x000faac8 MyApp`main(argc=1, argv=0x2fd0fd08) + 116 at main.m:16
  </code></pre>
  
  <p>EDIT:</p>
  
  <p>I have latest Xcode Version 5.0.1 (5A2053).</p>
  
  <p>I have created new app from scratch and ran it without issues. Then I put a breakpoint in <code>ViewController</code>'s <code>viewDidLoad</code> and tried to step over. Here I got another crash</p>
  
  <pre><code>* thread #1: tid = 0x2503, 0x3bb9d7c4 libobjc.A.dylib`objc_msgSendSuper2 + 4, queue = 'com.apple.main-thread, stop reason = EXC_BAD_ACCESS (code=1, address=0x4)
      frame #0: 0x3bb9d7c4 libobjc.A.dylib`objc_msgSendSuper2 + 4
      frame #1: 0x000b913a test`-[ViewController viewDidLoad](self=0x1cda5c70, _cmd=0x361bd5db) + 62 at ViewController.m:19
      frame #2: 0x35d4b594 UIKit`-[UIViewController loadViewIfRequired] + 364
      frame #3: 0x35d8bd78 UIKit`-[UIWindow addRootViewControllerViewIfPossible] + 64
      frame #4: 0x35d87aec UIKit`-[UIWindow _setHidden:forced:] + 364
      frame #5: 0x35dc91e8 UIKit`-[UIWindow makeKeyAndVisible] + 60
      frame #6: 0x35d8c83e UIKit`-[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1666
      frame #7: 0x35d8484a UIKit`-[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 698
      frame #8: 0x35d2cc38 UIKit`-[UIApplication handleEvent:withNewEvent:] + 1004
      frame #9: 0x35d2c6cc UIKit`-[UIApplication sendEvent:] + 72
      frame #10: 0x35d2c11a UIKit`_UIApplicationHandleEvent + 6154
      frame #11: 0x37a1e5a2 GraphicsServices`_PurpleEventCallback + 590
      frame #12: 0x37a1e1d2 GraphicsServices`PurpleEventCallback + 34
      frame #13: 0x33ef9172 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 34
      frame #14: 0x33ef9116 CoreFoundation`__CFRunLoopDoSource1 + 138
      frame #15: 0x33ef7f98 CoreFoundation`__CFRunLoopRun + 1384
      frame #16: 0x33e6aebc CoreFoundation`CFRunLoopRunSpecific + 356
      frame #17: 0x33e6ad48 CoreFoundation`CFRunLoopRunInMode + 104
      frame #18: 0x35d83484 UIKit`-[UIApplication _run] + 668
      frame #19: 0x35d80300 UIKit`UIApplicationMain + 1120
      frame #20: 0x000b93bc test`main(argc=1, argv=0x2fd51d30) + 116 at main.m:16
      frame #21: 0x3bfd9b20 libdyld.dylib`start + 4
  </code></pre>
  
  <p>EDIT 2:</p>
  
  <p>Greg Clayton in the <a href="https://devforums.apple.com/thread/209484">XCode 5 Crashes while running the app on device</a> suggests following</p>
  
  <pre><code>Others have seen this issue.
  A few things to try:
  1 - Reboot your device and try again. The theory is an old developer disk image is already mounted and won't be unmounted until you reboot.
  2 - Re-install the OS on the device
  
  Hopefully #1 fixes your issue. Others have done #2 and had their issue fixed, but hopefully it doesn't require an OS re-install.
  </code></pre>
  
  <p>I did both and it didn't help.  </p>
  
  <p>I tried to use another device and it made a difference. Exceptions are still there if I use iPod Touch with iOS 6.1 but iPad with iOS 7.0.2 works fine.</p>
  
  <p>So, it looks like the issue is related to the iOS version installed on the device. I am still not sure what to do to fix it. </p>
  
  <p>EDIT 3:</p>
  
  <p>My Command Line Tools version matches my Xcode version (I have only one version of Command Line Tools, actually).</p>
  
  <p>The issues is probably not related to the code being debugged. It crashes with newly created Single View Application created by Xcode. And it crashes when stepping over trivial code:</p>
  
  <pre><code>- (void)viewDidLoad
  {
      [super viewDidLoad];
      // Do any additional setup after loading the view, typically from a nib.
  }
  </code></pre>
  
  <p>I <a href="https://devforums.apple.com/message/912164">have asked</a> on Apple Developer Forum and got following response from Jason Molenda:</p>
  
  <blockquote>
    <p>We're tracking a bug that sounds like what you're seeing here.  It is
    a subtle timing issue that requires a slightly slower host machine or
    a slightly slower device to hit.  It is primarily iPhone 4 and similar
    that will see this with iOS 7.  With iOS 6, iPhone 4 and iPhone 3GS
    devices are most likely to experience it. ...  This issue will only
    happen with Xcode 5.0.1.</p>
  </blockquote>
  
  <p>So, it seems like it's a bug in Xcode. </p>