iOS AutoLayout debug

iOSAutoLayoutDebug

po [[UIWindow keyWindow] _autolayoutTrace] // prints layouts ambiguity
po [UIViewController _printHierarchy] // prints view controllers hierarchy
po [view constraintsAffectingLayoutForAxis:0] // horizontal
po [view constraintsAffectingLayoutForAxis:1] // vertical

[view hasAmbiguousLayout] // BOOL
[view exerciseAmbiguityInLayout] // visualizing ambiguity
UIViewAlertForUnsatisfiableConstraints // symbolic breakpoint
UIConstraintBasedLayoutDebugging // symbolic breakpoint

expr (void)[CATransaction flush]

command alias objcpo po -l objc++ -O -- 
command alias objcexpr expr -l objc++ -O --

Swift:
e let $sv = unsafeBitCast(0x7fe33d355b10, UIStackView.self)
po $sv.constraintsAffectingLayoutForAxis(.Horizontal)
po $sv.constraintsAffectingLayoutForAxis(.Vertical)