Célula UICollectionView + UiLabel com AutoLayout

Estou tentando fixar um UILabel na célula pai. Adicionei quatro restrições (superior, inicial, final, inferior)que funciona bem no iOS 8.0, mas não no iOS 7.X. Por favor, veja a imagem abaixo:

[Clique aqui para ampliar]

O que estou fazendo errado? Por favor informar!

EDIT # 1

Parece que só está quebrado desde o Xcode 6 GM. Minha abordagem estava funcionando bem no Xcode 6 beta 7.

Além disso, se eu diminuir a largura da vista interna, ele lança o seguinte aviso:

2014-09-10 19:58:28.109 Test[57827:60b] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x799573a0 H:|-(8)-[UIView:0x798a86e0]   (Names: '|':UIView:0x798ae5d0 )>",
    "<NSLayoutConstraint:0x799573d0 H:[UIView:0x798a86e0]-(43)-|   (Names: '|':UIView:0x798ae5d0 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x798a8b00 h=--& v=--& H:[UIView:0x798ae5d0(50)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x799573d0 H:[UIView:0x798a86e0]-(43)-|   (Names: '|':UIView:0x798ae5d0 )>

Break on objc_exception_throw to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

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