kinkoi

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

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

expr (void)[CATransaction flush]