我看到调试器日志中出现错误：
Will attempt to recover by breaking constraint <NSLayoutConstraint:0x191f0920 H:[MPKnockoutButton:0x17a876b0]-(34)-[MPDetailSlider:0x17a8bc50](LTR)> 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.
我该如何打那个电话？它没有出现在我的代码中的任何地方。
这篇文章对我帮助 很大 ！
我添加了带有建议操作的 UIViewAlertForUnsatisfiableConstraints 符号断点：
Obj-C 项目
po [[UIWindow keyWindow] _autolayoutTrace]
斯威夫特项目
expr -l objc++ -O -- [[UIWindow keyWindow] _autolayoutTrace]
有了这个提示，日志变得更加详细，我更容易确定哪个视图的约束被破坏了。
UIWindow:0x7f88a8e4a4a0 | UILayoutContainerView:0x7f88a8f23b70 | | UINavigationTransitionView:0x7f88a8ca1970 | | | UIViewControllerWrapperView:0x7f88a8f2aab0
