断点调试

1，运行xcode，终端打印

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in  may also be helpful.
2017-06-10 19:32:19.843 QeelinGold-iOS[15040:7223903] 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. 
(
    "",
    "",
    "",
    "",
    "",
    ""
)
Will attempt to recover by breaking constraint 

The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in  may also be helpful.

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger. 这句话的意思可以添加一个 UIViewAlertForUnsatisfiableConstraints的断点
链接：http://blog.afantree.com/ios/debug-for-uiviewalertforunsatisfiableconstraints.html