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 <UIKit/UIView.h> 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. 
(
    "<MASLayoutConstraint:0x1366a8220 UIImageView:0x136709a10.height == 100>",
    "<MASLayoutConstraint:0x136709ee0 UIImageView:0x136709a10.top == UITableViewCellContentView:0x1366a7820.top + 4>",
    "<MASLayoutConstraint:0x13670cd40 UIView:0x13670c1c0.height == 0.3>",
    "<MASLayoutConstraint:0x13670b1a0 UIView:0x13670c1c0.top == UIImageView:0x136709a10.bottom + 15>",
    "<MASLayoutConstraint:0x13670d280 UIView:0x13670c1c0.bottom == UITableViewCellContentView:0x1366a7820.bottom>",
    "<NSLayoutConstraint:0x13670ed70 UITableViewCellContentView:0x1366a7820.height == 119.333>"
)
Will attempt to recover by breaking constraint 
<MASLayoutConstraint:0x1366a8220 UIImageView:0x136709a10.height == 100>
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> 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