为什么ActivityViewController在控制台中显示自动约束错误？

Question

我试图在我的应用程序中实现一个共享按钮，所以很自然地，我转向UIActivityViewController。出于某种原因，任何时候我按下分享按钮，它会弹出，我得到了我的日志中看到以下消息：

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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x7c0a65d0 V:[UIView:0x7c0a2fa0(<=528)]>", 
    "<NSLayoutConstraint:0x7c0a6540 UIView:0x7c0a2fa0.height == UIView:0x7c0a2e60.height>", 
    "<NSLayoutConstraint:0x7c0a7100 _UIAlertControllerView:0x7c0a27f0.height == UIView:0x7c0a2e60.height>", 
    "<NSLayoutConstraint:0x7c0b1660 V:[_UIAlertControllerView:0x7c0a27f0(568)]>" 
) 

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x7c0a65d0 V:[UIView:0x7c0a2fa0(<=528)]> 

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger. 
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful. 
2015-06-20 15:32:43.885 App[19268:300248] 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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x78fc3e70 V:[UIView:0x78ff1eb0(<=528)]>", 
    "<NSLayoutConstraint:0x78fc3de0 UIView:0x78ff1eb0.height == UIView:0x78fb9670.height>", 
    "<NSLayoutConstraint:0x78fc5aa0 _UIAlertControllerView:0x78ff69f0.height == UIView:0x78fb9670.height>", 
    "<NSLayoutConstraint:0x78f58860 V:[_UIAlertControllerView:0x78ff69f0(568)]>" 
) 

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x78fc3e70 V:[UIView:0x78ff1eb0(<=528)]> 

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger. 
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful. 
2015-06-20 15:32:48.691 App[19268:300248] viewServiceDidTerminateWithError: Error Domain=_UIViewServiceInterfaceErrorDomain Code=3 "The operation couldn’t be completed. (_UIViewServiceInterfaceErrorDomain error 3.)" UserInfo=0x79982700 {Message=Service Connection Interrupted} 

调用它时我没有做任何幻想，只是最低限度：

let someText:String = "Hello" 
     let activityViewController = UIActivityViewController(activityItems: [someText], applicationActivities: nil) 
     activityViewController.excludedActivityTypes = [ 
      UIActivityTypePostToWeibo, 
      UIActivityTypePrint, 
      UIActivityTypeCopyToPasteboard, 
      UIActivityTypeAssignToContact, 
      UIActivityTypeSaveToCameraRoll, 
      UIActivityTypeAddToReadingList, 
      UIActivityTypePostToFlickr, 
      UIActivityTypePostToVimeo, 
      UIActivityTypePostToTencentWeibo 
     ]   self.navigationController!.presentViewController(activityViewController, 
      animated: true, 
      completion: nil) 

这会是从Xcode中的β7/9的iOS错误？或者我错过了什么？我应该担心吗？

Answer 1

或者：

1. 这是一个苹果的错误 - 因为它仍处于测试阶段它只要报http://radar.apple.com
2. 您从一个超大的视图控制器（以帧错误？），然后呈现模式限制V:[UIView:0x7c0a2fa0(<=528)中断

你应该担心吗？ 1.它不会导致崩溃，但它仍然是一个程序员错误的迹象，日志在那里，理想情况下，如果你故意要打破它们，你会提供约束的优先级