We are running into a very strange bug in Swift 2/XCode 7b5.
We have a .Top Constraint with a constant that we are adjusting based on a separate scrollview.contentOffset.y to get a paralax effort.
50-60% of the time it works correctly. The rest of the time I can see the Constraint getting updated, but no visual change takes place
print(Constraint?)
Optional(<NSLayoutConstraint:0x7f82621c6d40 V:|-(21)-[UICollectionView:0x7f825f87da00] (Names: '|':UIView:0x7f82621c4890 )>)We are sure to call
self.view.layoutIfNeeded()directly after we update the Constraint
All the views and constraints are being created in code.