Q:

Reuse identifier in nib does not match the identifier used to register the nib

I have a Framework/Module written in Swift which provides some custom controls with IBDesignable functionality. 
Currently I am working on a control based on a CollectionView. The CollectionView and the custom CollectionViewCell are build in Nib files. To load the CollectionViewNib and add the Designable funcionality I use this NibDesignable class. After initalising the CollectionView I register the CollectionViewCell as following:
let cellIdentifier = "collectionViewCell"

required public init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    self.setup()
}

override init(frame: CGRect) {
    super.init(frame: frame)
    self.setup()
}

private func setup() {
    let bundle = NSBundle(forClass: self.dynamicType)
    self.collectionView.registerNib(UINib(nibName: "CollectionViewCell", bundle: bundle), forCellWithReuseIdentifier: self.cellIdentifier)
}

After adding my Framework as Embedded Binary to another app I can use my new custom CollectionView as expected, but unfortunately the Designable functionality isn´t working well, instead I get the following error message:
IB Designables: Failed to update auto layout status: 
The agent raised a "NSInternalInconsistencyException" exception: 
view reuse identifier in nib (ibCollectionViewCell) does not match the identifier used to register the nib (collectionViewCell)

As describe above my Control works in the Simulator and on my Phone, so no I don´t use different identifiers. I don´t know where XCode gets this 
ibCollectionViewCell identifier, but when I use it as identifier for my CollectionViewCell every thing works like a charm.
Any ideas where this identifier comes from and why XCode can´t load my custom CollectionViewCell with my own identifier?

A:

After updating from XCode 7 Beta 4 to Beta 5 the error was gone. So I assume there was something buggy in the previous version

