gistfile1.md

On iOS 8 beta 4, this constraint:

[NSLayoutConstraint constraintWithItem:_galleryView 
                             attribute:NSLayoutAttributeLeading 
                             relatedBy:NSLayoutRelationEqual 
                                toItem:self.view 
                             attribute:NSLayoutAttributeLeft 
                            multiplier:1.0f 
                              constant:0];

causes the following exception to be thrown:

Fatal Exception: NSInvalidArgumentException
*** +[NSLayoutConstraint constraintWithItem:attribute:relatedBy:toItem:attribute:multiplier:constant:]: 
A constraint cannot be made between a leading/trailing attribute and a right/left attribute. 
Use leading/trailing for both or neither.

And yes, the constraint doesn't make much sense to begin with, but it did work on iOS 7.