SnapKit: crash: Updated constraint could not find existing matching constraint to update

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• I have looked at the Documentation
• I have read the F.A.Q.

Issue Info

Info	Value
Platform	ios
Platform Version	10
SnapKit Version	0.40.0 (2e4cebf41d8bd0833487381590ed90c38b9a2491)
Integration Method	carthage

Issue Description

I’ve just migrated my app to Swift3 and hence also switched to version 0.40 unfortunately it now crashes on startup. I am seeing

NSHashTable {
[0] <SnapKit.LayoutConstraint:0x6000000bf3e0@ReloadView.swift#47 UILabel:0x7faa7bc38770.top == Foo.ReloadView:0x7faa7bc35340.top + 20.0>
}
 NSHashTable {
[0] <SnapKit.LayoutConstraint:0x6000000bf3e0@ReloadView.swift#47 UILabel:0x7faa7bc38770.top == Foo.ReloadView:0x7faa7bc35340.top + 20.0>
}

fatal error: Updated constraint could not find existing matching constraint to update: <SnapKit.LayoutConstraint:0x6000000bf440@ReloadView.swift#48 UILabel:0x7faa7bc38770.left == Foo.ReloadView:0x7faa7bc35340.left + 20.0>: file /project/Carthage/Checkouts/SnapKit/Source/Constraint.swift, line 233

A stripped down version of the view controller and view looks like this:

class ReloadView: UIView {

    override init(frame: CGRect) {
        super.init(frame: frame)
        configure()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        configure()
    }

    convenience init() {
        self.init(frame: CGRect.zero)
    }

    func configure() {

        let label = UILabel()
        let button = UIButton(type: UIButtonType.roundedRect)

        addSubview(label)
        addSubview(button)

        let padding = 20

        label.snp.updateConstraints { make in
            make.top.equalTo(padding)
            make.left.equalTo(self).offset(padding)
            make.right.equalTo(self).offset(-padding)
            make.width.equalTo(300)
        }

        button.snp.updateConstraints { make in
            make.top.equalTo(label.snp.bottom).offset(padding)
            make.left.equalTo(padding)
            make.width.equalTo(self).offset(-2*padding)
            make.bottom.equalTo(0).offset(-padding)
        }
    }
}

class FooViewController: UIViewController {

    private var reloadView: ReloadView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let reloadView = ReloadView()
        self.reloadView = reloadView

        view.addSubview(reloadView)

        reloadView.snp.updateConstraints { make in
            // make.center.equalToSuperview()
            make.edges.equalTo(view.snp.edges)
        }

    }
}