title: How to figure out what makes my iOS app crash (EXC_BREAKPOINT)?
body: <p>How can I know where exactly did my app crash ?<br>
  I receive a lot of crash from my users but I can't reproduce the crash myself and the crash log does not indicate a specific line:</p>
  
  <pre><code>Thread : Crashed: com.apple.main-thread
  0  myapp                  0x22d1d4 specialized ItemType.init(coder : NSCoder) -&gt; ItemType? (ItemType.swift)
  1  myapp                  0x22c72c @objc ItemType.init(coder : NSCoder) -&gt; ItemType? (ItemType.swift)
  2  EventKitUI                     0x234734a5 (Missing)
  3  EventKitUI                     0x23479639 (Missing)
  4  EventKitUI                     0x234161db (Missing)
  5  EventKitUI                     0x234734a5 (Missing)
  6  EventKitUI                     0x234728d3 (Missing)
  7  myapp                  0x1e9df4 specialized Item.init(coder : NSCoder) -&gt; Item? (Item.swift:162)
  8  myapp                  0x1db9b8 @objc Item.init(coder : NSCoder) -&gt; Item? (Item.swift)
  9  EventKitUI                     0x234734a5 (Missing)
  10 EventKitUI                     0x234728d3 (Missing)
  11 EventKitUI                     0x23471bc7 (Missing)
  12 myapp                  0x26f370 savedSearchList.getLastItem() -&gt; Item! (savedItemList.swift:71)
  13 myapp                  0x26c008 specialized MenuInitializerViewController.getSideMenuViewController() -&gt; UIViewController (MenuInitializerViewController.swift:39)
  14 myapp                  0x18388c SharedAppDelegate.showMainInterface() -&gt; () (SharedAppDelegate.swift:427)
  15 myapp                  0x18398c @objc SharedAppDelegate.showMainInterface() -&gt; () (SharedAppDelegate.swift)
  16 myapp                  0x188a48 SharedAppDelegate.(retreiveFirstData(SharedAppDelegate) -&gt; () -&gt; ()).(closure #1) (SharedAppDelegate.swift:290)
  17 myapp                  0x2657a4 partial apply for UserAppData.(getFirstData(UserAppData) -&gt; (() -&gt; (), failure : (error : NSError) -&gt; ()) -&gt; ()).(closure #3) (UserAppData.swift:45)
  18 myapp                  0x263828 partial apply for thunk (UserAppData.swift)
  19 myapp                  0x268c28 UserAppData.(getDiffusionsGroup(UserAppData) -&gt; (() -&gt; (), failure : (error : NSError) -&gt; ()) -&gt; ()).(successBlock #1)(AFHTTPRequestOperation!, responseObject : AnyObject!)() (UserAppData.swift:788)
  20 myapp                  0x266684 partial apply for UserAppData.(getDiffusionsGroup(UserAppData) -&gt; (() -&gt; (), failure : (error : NSError) -&gt; ()) -&gt; ()).(successBlock #1)(AFHTTPRequestOperation!, responseObject : AnyObject!)() (UserAppData.swift)
  21 libtzupdate.dylib              0x344ffe2f (Missing)
  22 libtzupdate.dylib              0x344ffe1b (Missing)
  23 libtzupdate.dylib              0x345046c9 (Missing)
  24 CoreAudio                      0x226dc535 (Missing)
  25 CoreAudio                      0x226daa2f (Missing)
  26 CoreAudio                      0x2262d0d9 (Missing)
  27 CoreAudio                      0x2262cecd (Missing)
  28 GeoServices                    0x2b9a2af9 (Missing)
  29 UIKit                          0x268b62dd UIApplicationMain + 144
  30 myapp                  0x10f2d4 main (AppDelegate.swift:16)
  31 libtzupdate.dylib              0x34528873 (Missing)
  </code></pre>
  
  <p>I understand that it might come from ItemType unarchive initializer, but I don't see what could be wrong with it:</p>
  
  <pre><code>required convenience init?(coder aDecoder: NSCoder)
  {
      self.index = aDecoder.decodeIntegerForKey("index")
      self.name = aDecoder.decodeObjectForKey("name") as! String
      self.id = aDecoder.decodeObjectForKey("id") as! String
      self.type = Type(rawValue: aDecoder.decodeIntegerForKey("type")) ?? .Default
  }
  </code></pre>