Cannot equal height to Superview in Xcode 11
You can set your view equal to the Safe Area.
If you still rely on having it equal to the root view itself, you can modify the constraint in the Attributes Inspector:
I have sent a bug report to Apple yesterday and also found the following discussion in Apple forums. I don't think I am the only developer experiencing this issue.
Xcode 11 Add "Equal Width to Superview" Constraint?
I am sure Apple will create a patch for this problem soon. So I decided to create a temporary solution by adding a new UIView named "Propotional View Helper" right under the root view. I gave trailing, leading, bottom and top constraints to its superview. Now I a able to drag to make equal width & height constraints to the superview.
First do "Equal Widths " to any other UIView element .
Go to Attributes inspector of the equal width contraint .
Replace the Second Item with Superview.Width.