添加log日志打印异常的symbolic Breakpoint

1"This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes"

屏幕快照 2017-07-25 下午6.17.39.png

2.Will attempt to recover by breaking constraint

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.

屏幕快照 2017-07-25 下午6.18.01.png

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