title: |-(20)-[UIInputSetContainerView constraint breaks when call-in status bar gets visible
body: <p>My app breaks a constraint when I present the "Call-in" status bar by pressing Command+Y in the simulator. It only happens the first time it presents the call-in bar. Everything looks as it supposed to, but the log prints out the following:</p>
  
  <pre><code>Unable to simultaneously satisfy constraints.
      Probably at least one of the constraints in the following list is one you don't want. 
      Try this: 
          (1) look at each constraint and try to figure out which you don't expect; 
          (2) find the code that added the unwanted constraint or constraints and fix it. 
  (
      "&lt;NSLayoutConstraint:0x7fb4cb9b2b60 V:|-(20)-[UIInputSetContainerView:0x7fb4cb9b1190]   (Names: '|':UITextEffectsWindow:0x7fb4cba003f0 )&gt;",
      "&lt;NSLayoutConstraint:0x7fb4cb942100 'UIInputWindowController-top' V:|-(0)-[UIInputSetContainerView:0x7fb4cb9b1190]   (Names: '|':UITextEffectsWindow:0x7fb4cba003f0 )&gt;"
  )
  
  Will attempt to recover by breaking constraint 
  &lt;NSLayoutConstraint:0x7fb4cb9b2b60 V:|-(20)-[UIInputSetContainerView:0x7fb4cb9b1190]   (Names: '|':UITextEffectsWindow:0x7fb4cba003f0 )&gt;
  
  Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
  The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in &lt;UIKit/UIView.h&gt; may also be helpful.
  </code></pre>
  
  <p>This is the call stack when it breaks for <code>UIViewAlertForUnsatisfiableConstraints</code>:</p>
  
  <pre><code>* thread #1: tid = 0x17582f, 0x0000000109bbb4c6 UIKit`UIViewAlertForUnsatisfiableConstraints, queue = 'com.apple.main-thread', stop reason = breakpoint 3.1
      frame #0: 0x0000000109bbb4c6 UIKit`UIViewAlertForUnsatisfiableConstraints
      frame #1: 0x0000000109bbb8b2 UIKit`-[UIView(UIConstraintBasedLayout_EngineDelegate) engine:willBreakConstraint:dueToMutuallyExclusiveConstraints:] + 113
      frame #2: 0x0000000107ea672b Foundation`-[NSISEngine handleUnsatisfiableRowWithHead:body:usingInfeasibilityHandlingBehavior:mutuallyExclusiveConstraints:] + 489
      frame #3: 0x0000000107d07801 Foundation`-[NSISEngine fixUpValueRestrictionViolationsWithInfeasibilityHandlingBehavior:] + 613
      frame #4: 0x0000000107d07537 Foundation`-[NSISEngine optimize] + 134
      frame #5: 0x0000000107d07da4 Foundation`-[NSISEngine withBehaviors:performModifications:] + 245
      frame #6: 0x0000000109bb5a4b UIKit`-[UIView(AdditionalLayoutSupport) _withAutomaticEngineOptimizationDisabledIfEngineExists:] + 58
      frame #7: 0x0000000109bb658e UIKit`-[UIView(AdditionalLayoutSupport) updateConstraintsIfNeeded] + 254
      frame #8: 0x0000000109ba6c46 UIKit`-[UIWindow(UIConstraintBasedLayout) updateConstraintsIfNeeded] + 108
      frame #9: 0x0000000109bb72a3 UIKit`-[UIView(AdditionalLayoutSupport) _updateConstraintsAtEngineLevelIfNeeded] + 272
      frame #10: 0x00000001093979b3 UIKit`-[UIView(Hierarchy) layoutBelowIfNeeded] + 845
      frame #11: 0x000000010936eb8b UIKit`-[UIWindow handleStatusBarChangeFromHeight:toHeight:] + 1284
      frame #12: 0x0000000109703b5b UIKit`-[UITextEffectsWindow handleStatusBarChangeFromHeight:toHeight:] + 100
    * frame #13: 0x00000001093726a7 UIKit`+[UIWindow _noteStatusBarHeightChanged:oldHeight:forAutolayoutRootViewsOnly:] + 364
      frame #14: 0x0000000109303a52 UIKit`-[UIApplication statusBar:willAnimateFromHeight:toHeight:duration:animation:] + 265
      frame #15: 0x00000001099115bb UIKit`-[UIStatusBar _requestStyleAttributes:animationParameters:forced:] + 885
      frame #16: 0x0000000109910fbf UIKit`-[UIStatusBar requestStyle:animationParameters:forced:] + 437
      frame #17: 0x0000000109910d0d UIKit`-[UIStatusBar requestStyle:animated:forced:] + 90
      frame #18: 0x00000001099160a6 UIKit`-[UIStatusBar statusBarServer:didReceiveStyleOverrides:] + 56
      frame #19: 0x0000000109904b05 UIKit`_UIStatusBarReceivedStyleOverrides + 45
      frame #20: 0x0000000109909058 UIKit`_XReceivedStyleOverrides + 33
      frame #21: 0x0000000110d67fa8 AppSupport`migHelperRecievePortCallout + 208
      frame #22: 0x000000010896c289 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 41
      frame #23: 0x000000010896c1f9 CoreFoundation`__CFRunLoopDoSource1 + 473
      frame #24: 0x0000000108961970 CoreFoundation`__CFRunLoopRun + 2272
      frame #25: 0x0000000108960e08 CoreFoundation`CFRunLoopRunSpecific + 488
      frame #26: 0x000000010e360ad2 GraphicsServices`GSEventRunModal + 161
      frame #27: 0x00000001092f330d UIKit`UIApplicationMain + 171
      frame #28: 0x00000001074e252f AppName`main(argc=1, argv=0x00007fff5872e688) + 111 at main.m:16
      frame #29: 0x000000010aa6b92d libdyld.dylib`start + 1
      frame #30: 0x000000010aa6b92d libdyld.dylib`start + 1
  </code></pre>
  
  <p>Do you have any idea why the constraint breaks? I haven't added any constraints to the <code>UIInputSetContainerView</code>, <code>UITextEffectsWindow</code> or <code>UIInputWindowController</code>.</p>
  
  <p><strong>EDIT:</strong> My question has been marked as a possible duplicate, but I <strong>DO NOT</strong> recommend or agree with <a href="https://stackoverflow.com/a/33411423/1118969">the answer</a> that is provided in the <a href="https://stackoverflow.com/questions/33112762/in-call-status-bar-unable-to-satisfy-constraints">other question</a>. It is very risky to remove Apple's own constraints, just to get rid of this warning. I would not recommend doing that. Which is why I also find the duplicate flag wrong (<em>This question has been asked before and already has an answer.</em>), because the answer is not the one I am looking for.</p>