Ошибки UIViewAlertForUnsatisfiableConstraints при работе с динамическим c размером заголовка UICollectionView

Question

Intro

Привет,

Я пытаюсь присвоить ячейке заголовка моей коллекцииView динамический c размер ячейки. Ячейка, которая используется в качестве заголовка, также используется как «обычная» ячейка в другом collectionView. Там, работа с динамическим размером ячейки c работает отлично.

Вот как создается collectionView:

private lazy var timelineCollectionView: UICollectionView = {
    let flowLayout = UICollectionViewFlowLayout()
    flowLayout.scrollDirection = .vertical
    flowLayout.estimatedItemSize = CGSize(width: self.view.frame.width, height: 10)
    flowLayout.minimumInteritemSpacing = 0
    flowLayout.minimumLineSpacing = 0

    let cv = UICollectionView(frame: .zero, collectionViewLayout: flowLayout)
    cv.alwaysBounceVertical = true
    cv.contentInsetAdjustmentBehavior = .never
    cv.backgroundColor = .clear
    cv.scrollIndicatorInsets = UIEdgeInsets(top: self.coloredTitleBarHeight - self.getStatusBarHeight(), left: 0, bottom: 0, right: 0)

    cv.delegate = self
    cv.dataSource = self
    cv.register(TLContentCell.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "content-header-cell")

    return cv
}()

Я следовал этот урок для работы с динамической c высотой ячейки.

После урока приведен фрагмент кода в моей ячейке:

private lazy var width: NSLayoutConstraint = {
        let width = contentView.widthAnchor.constraint(equalToConstant: bounds.size.width)
        width.isActive = true
        return width
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        contentView.translatesAutoresizingMaskIntoConstraints = false
        contentView.backgroundColor = UIColor.white
    }

    override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize {
        width.constant = bounds.size.width
        return contentView.systemLayoutSizeFitting(CGSize(width: targetSize.width, height: 1))
    }

func setupViews() {
     // view setup happens here
     if let lastSubview = contentView.subviews.last {
         contentView.bottomAnchor.constraint(equalTo: lastSubview.bottomAnchor, constant: 0).isActive = true
     }
}

Опять же, этот код работает совершенно нормально, если я использую ячейку как обычную ячейку, а не в верхнем или нижнем колонтитуле collectionView.

Теперь я просто хотел использовать это в шапке. Поскольку невозможно предоставить что-то вроде estimatedItemSize для ячейки заголовка, я использую следующий подход, найденный в этом SO сообщении :

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
        let indexPath = IndexPath(row: 0, section: section)
        let headerView = self.collectionView(collectionView, viewForSupplementaryElementOfKind: UICollectionView.elementKindSectionHeader, at: indexPath) as! TLContentCell
        headerView.layoutIfNeeded()

        return headerView.systemLayoutSizeFitting(CGSize(width: collectionView.frame.width, height: UIView.layoutFittingExpandedSize.height),
        withHorizontalFittingPriority: .required, // Width is fixed
        verticalFittingPriority: .fittingSizeLevel) // Height can be as large as needed
    }

И действительно, размер ячейки заголовка корректно изменяется. Однако UIKit печатает, казалось бы, бесконечное количество UIViewAlertForUnsatisfiableConstraints ошибок (сокращено из-за ограничения символов SO):

    2020-01-16 15:29:00.427001+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x600000024820 MyApp.DefaultLabel:0x7fa6fc579090'3d'.width == 17.6667   (active)>",
    "<NSLayoutConstraint:0x600000024780 MyApp.AnimatedButton:0x7fa6fc5786d0.width == 20   (active)>",
    "<NSLayoutConstraint:0x6000000245f0 UIImageView:0x7fa6fc578020.width == 45   (active)>",
    "<NSLayoutConstraint:0x600000024550 H:|-(0)-[UIImageView:0x7fa6fc578020](LTR)   (active, names: '|':UIView:0x7fa6fc578980 )>",
    "<NSLayoutConstraint:0x600000024730 MyApp.AnimatedButton:0x7fa6fc5786d0.right == UIView:0x7fa6fc578980.right   (active)>",
    "<NSLayoutConstraint:0x6000000247d0 MyApp.DefaultLabel:0x7fa6fc579090'3d'.right == MyApp.AnimatedButton:0x7fa6fc5786d0.left - 4   (active)>",
    "<NSLayoutConstraint:0x600000024a50 H:[UIImageView:0x7fa6fc578020]-(8)-[MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'](LTR)   (active)>",
    "<NSLayoutConstraint:0x600000024910 MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'.right == MyApp.DefaultLabel:0x7fa6fc579090'3d'.left   (active)>",
    "<NSLayoutConstraint:0x600000024be0 H:|-(16)-[UIView:0x7fa6fc578980](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000024c30 UIView:0x7fa6fc578980.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x6000000245f0 UIImageView:0x7fa6fc578020.width == 45   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.427892+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x6000000252c0 UIStackView:0x7fa6fc57a470.width == 80   (active)>",
    "<NSLayoutConstraint:0x600000024fa0 H:|-(0)-[UIImageView:0x7fa6fc57a610](LTR)   (active, names: '|':UIView:0x7fa6fc57a300 )>",
    "<NSLayoutConstraint:0x600000025040 UIImageView:0x7fa6fc57a610.right == UIStackView:0x7fa6fc57a470.left - 8   (active)>",
    "<NSLayoutConstraint:0x600000025220 UIStackView:0x7fa6fc57a470.right == UIView:0x7fa6fc57a300.right   (active)>",
    "<NSLayoutConstraint:0x600000025360 H:|-(0)-[UIView:0x7fa6fc57a300](LTR)   (active, names: '|':UIView:0x7fa6fc57a010 )>",
    "<NSLayoutConstraint:0x6000000253b0 UIView:0x7fa6fc57a300.right == UIView:0x7fa6fc57a010.right   (active)>",
    "<NSLayoutConstraint:0x600000025590 H:|-(16)-[UIView:0x7fa6fc57a010](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x6000000255e0 UIView:0x7fa6fc57a010.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x6000000252c0 UIStackView:0x7fa6fc57a470.width == 80   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.428596+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x600000024820 MyApp.DefaultLabel:0x7fa6fc579090'3d'.width == 17.6667   (active)>",
    "<NSLayoutConstraint:0x600000024780 MyApp.AnimatedButton:0x7fa6fc5786d0.width == 20   (active)>",
    "<NSLayoutConstraint:0x600000024550 H:|-(0)-[UIImageView:0x7fa6fc578020](LTR)   (active, names: '|':UIView:0x7fa6fc578980 )>",
    "<NSLayoutConstraint:0x600000024730 MyApp.AnimatedButton:0x7fa6fc5786d0.right == UIView:0x7fa6fc578980.right   (active)>",
    "<NSLayoutConstraint:0x6000000247d0 MyApp.DefaultLabel:0x7fa6fc579090'3d'.right == MyApp.AnimatedButton:0x7fa6fc5786d0.left - 4   (active)>",
    "<NSLayoutConstraint:0x600000024a50 H:[UIImageView:0x7fa6fc578020]-(8)-[MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'](LTR)   (active)>",
    "<NSLayoutConstraint:0x600000024910 MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'.right == MyApp.DefaultLabel:0x7fa6fc579090'3d'.left   (active)>",
    "<NSLayoutConstraint:0x600000024be0 H:|-(16)-[UIView:0x7fa6fc578980](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000024c30 UIView:0x7fa6fc578980.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000024780 MyApp.AnimatedButton:0x7fa6fc5786d0.width == 20   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.429543+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x600000024820 MyApp.DefaultLabel:0x7fa6fc579090'3d'.width == 17.6667   (active)>",
    "<NSLayoutConstraint:0x600000024550 H:|-(0)-[UIImageView:0x7fa6fc578020](LTR)   (active, names: '|':UIView:0x7fa6fc578980 )>",
    "<NSLayoutConstraint:0x600000024730 MyApp.AnimatedButton:0x7fa6fc5786d0.right == UIView:0x7fa6fc578980.right   (active)>",
    "<NSLayoutConstraint:0x6000000247d0 MyApp.DefaultLabel:0x7fa6fc579090'3d'.right == MyApp.AnimatedButton:0x7fa6fc5786d0.left - 4   (active)>",
    "<NSLayoutConstraint:0x600000024a50 H:[UIImageView:0x7fa6fc578020]-(8)-[MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'](LTR)   (active)>",
    "<NSLayoutConstraint:0x600000024910 MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'.right == MyApp.DefaultLabel:0x7fa6fc579090'3d'.left   (active)>",
    "<NSLayoutConstraint:0x600000024be0 H:|-(16)-[UIView:0x7fa6fc578980](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000024c30 UIView:0x7fa6fc578980.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000024820 MyApp.DefaultLabel:0x7fa6fc579090'3d'.width == 17.6667   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.430324+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x6000000250e0 V:|-(0)-[UIStackView:0x7fa6fc57a470]   (active, names: '|':UIView:0x7fa6fc57a300 )>",
    "<NSLayoutConstraint:0x600000025090 UIStackView:0x7fa6fc57a470.bottom == UIView:0x7fa6fc57a300.bottom   (active)>",
    "<NSLayoutConstraint:0x600000025400 UIView:0x7fa6fc57a300.height == 0.5625*UIView:0x7fa6fc57a300.width   (active)>",
    "<NSLayoutConstraint:0x600000025360 H:|-(0)-[UIView:0x7fa6fc57a300](LTR)   (active, names: '|':UIView:0x7fa6fc57a010 )>",
    "<NSLayoutConstraint:0x6000000253b0 UIView:0x7fa6fc57a300.right == UIView:0x7fa6fc57a010.right   (active)>",
    "<NSLayoutConstraint:0x600000025590 H:|-(16)-[UIView:0x7fa6fc57a010](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x6000000255e0 UIView:0x7fa6fc57a010.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>",
    "<NSLayoutConstraint:0x600000026210 'UISV-canvas-connection' UIStackView:0x7fa6fc57a470.top == UIImageView:0x7fa6fc57a7e0.top   (active)>",
    "<NSLayoutConstraint:0x600000026260 'UISV-canvas-connection' V:[UIImageView:0x7fa6fc57ab80]-(0)-|   (active, names: '|':UIStackView:0x7fa6fc57a470 )>",
    "<NSLayoutConstraint:0x600000026300 'UISV-fill-equally' UIImageView:0x7fa6fc57a9b0.height == UIImageView:0x7fa6fc57a7e0.height   (active)>",
    "<NSLayoutConstraint:0x6000000263a0 'UISV-fill-equally' UIImageView:0x7fa6fc57ab80.height == UIImageView:0x7fa6fc57a7e0.height   (active)>",
    "<NSLayoutConstraint:0x6000000262b0 'UISV-spacing' V:[UIImageView:0x7fa6fc57a7e0]-(8)-[UIImageView:0x7fa6fc57a9b0]   (active)>",
    "<NSLayoutConstraint:0x600000026350 'UISV-spacing' V:[UIImageView:0x7fa6fc57a9b0]-(8)-[UIImageView:0x7fa6fc57ab80]   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000026350 'UISV-spacing' V:[UIImageView:0x7fa6fc57a9b0]-(8)-[UIImageView:0x7fa6fc57ab80]   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.431297+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x60000003df90 UIImageView:0x7fa6fc576970.width == 13   (active)>",
    "<NSLayoutConstraint:0x60000003e030 H:|-(4)-[UIImageView:0x7fa6fc576970](LTR)   (active, names: '|':UIView:0x7fa6fc56e2d0 )>",
    "<NSLayoutConstraint:0x60000003e940 H:[UIImageView:0x7fa6fc576970]-(4)-[MyApp.DefaultLabel:0x7fa6fc576700'by linus_hologram '](LTR)   (active)>",
    "<NSLayoutConstraint:0x60000003e440 MyApp.DefaultLabel:0x7fa6fc576700'by linus_hologram '.right == UIView:0x7fa6fc56e2d0.right - 4   (active)>",
    "<NSLayoutConstraint:0x6000000e2bc0 H:|-(16)-[UIView:0x7fa6fc56e2d0](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000023930 UIView:0x7fa6fc56e2d0.right <= UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000025ae0 MyApp.DefaultLabel:0x7fa6fc575060'0'.right == UIView:0x7fa6fc57c3e0.right   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.434486+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x60000003e030 H:|-(4)-[UIImageView:0x7fa6fc576970](LTR)   (active, names: '|':UIView:0x7fa6fc56e2d0 )>",
    "<NSLayoutConstraint:0x60000003e940 H:[UIImageView:0x7fa6fc576970]-(4)-[MyApp.DefaultLabel:0x7fa6fc576700'by linus_hologram '](LTR)   (active)>",
    "<NSLayoutConstraint:0x60000003e440 MyApp.DefaultLabel:0x7fa6fc576700'by linus_hologram '.right == UIView:0x7fa6fc56e2d0.right - 4   (active)>",
    "<NSLayoutConstraint:0x6000000e2bc0 H:|-(16)-[UIView:0x7fa6fc56e2d0](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000023930 UIView:0x7fa6fc56e2d0.right <= UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x60000003e940 H:[UIImageView:0x7fa6fc576970]-(4)-[MyApp.DefaultLabel:0x7fa6fc576700'by linus_hologram '](LTR)   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.435062+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x600000024550 H:|-(0)-[UIImageView:0x7fa6fc578020](LTR)   (active, names: '|':UIView:0x7fa6fc578980 )>",
    "<NSLayoutConstraint:0x600000024730 MyApp.AnimatedButton:0x7fa6fc5786d0.right == UIView:0x7fa6fc578980.right   (active)>",
    "<NSLayoutConstraint:0x6000000247d0 MyApp.DefaultLabel:0x7fa6fc579090'3d'.right == MyApp.AnimatedButton:0x7fa6fc5786d0.left - 4   (active)>",
    "<NSLayoutConstraint:0x600000024a50 H:[UIImageView:0x7fa6fc578020]-(8)-[MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'](LTR)   (active)>",
    "<NSLayoutConstraint:0x600000024910 MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'.right == MyApp.DefaultLabel:0x7fa6fc579090'3d'.left   (active)>",
    "<NSLayoutConstraint:0x600000024be0 H:|-(16)-[UIView:0x7fa6fc578980](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000024c30 UIView:0x7fa6fc578980.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000024a50 H:[UIImageView:0x7fa6fc578020]-(8)-[MyApp.DefaultLabel:0x7fa6fc578460'@unitedholograms'](LTR)   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.435727+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x600000024550 H:|-(0)-[UIImageView:0x7fa6fc578020](LTR)   (active, names: '|':UIView:0x7fa6fc578980 )>",
    "<NSLayoutConstraint:0x600000024730 MyApp.AnimatedButton:0x7fa6fc5786d0.right == UIView:0x7fa6fc578980.right   (active)>",
    "<NSLayoutConstraint:0x6000000247d0 MyApp.DefaultLabel:0x7fa6fc579090'3d'.right == MyApp.AnimatedButton:0x7fa6fc5786d0.left - 4   (active)>",
    "<NSLayoutConstraint:0x600000024960 H:[UIImageView:0x7fa6fc578020]-(8)-[MyApp.DefaultLabel:0x7fa6fc5781f0'MyApp'](LTR)   (active)>",
    "<NSLayoutConstraint:0x6000000249b0 MyApp.DefaultLabel:0x7fa6fc5781f0'MyApp'.right == MyApp.DefaultLabel:0x7fa6fc579090'3d'.left   (active)>",
    "<NSLayoutConstraint:0x600000024be0 H:|-(16)-[UIView:0x7fa6fc578980](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000024c30 UIView:0x7fa6fc578980.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000024960 H:[UIImageView:0x7fa6fc578020]-(8)-[MyApp.DefaultLabel:0x7fa6fc5781f0'MyApp'](LTR)   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.436212+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x600000024fa0 H:|-(0)-[UIImageView:0x7fa6fc57a610](LTR)   (active, names: '|':UIView:0x7fa6fc57a300 )>",
    "<NSLayoutConstraint:0x600000025040 UIImageView:0x7fa6fc57a610.right == UIStackView:0x7fa6fc57a470.left - 8   (active)>",
    "<NSLayoutConstraint:0x600000025220 UIStackView:0x7fa6fc57a470.right == UIView:0x7fa6fc57a300.right   (active)>",
    "<NSLayoutConstraint:0x600000025360 H:|-(0)-[UIView:0x7fa6fc57a300](LTR)   (active, names: '|':UIView:0x7fa6fc57a010 )>",
    "<NSLayoutConstraint:0x6000000253b0 UIView:0x7fa6fc57a300.right == UIView:0x7fa6fc57a010.right   (active)>",
    "<NSLayoutConstraint:0x600000025590 H:|-(16)-[UIView:0x7fa6fc57a010](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x6000000255e0 UIView:0x7fa6fc57a010.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000025220 UIStackView:0x7fa6fc57a470.right == UIView:0x7fa6fc57a300.right   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-01-16 15:29:00.436954+0100 MyApp[1542:65269] [LayoutConstraints] 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. 
(
    "<NSLayoutConstraint:0x600000025680 H:|-(0)-[MyApp.PostInteractionButton:0x7fa6fc5720f0](LTR)   (active, names: '|':UIView:0x7fa6fc579e80 )>",
    "<NSLayoutConstraint:0x600000025720 MyApp.PostInteractionButton:0x7fa6fc5720f0.right == MyApp.DefaultLabel:0x7fa6fc573090'1'.left - 8   (active)>",
    "<NSLayoutConstraint:0x600000025810 MyApp.DefaultLabel:0x7fa6fc573090'1'.right == UIView:0x7fa6fc579e80.right   (active)>",
    "<NSLayoutConstraint:0x600000025ef0 H:|-(16)-[UIStackView:0x7fa6fc579cf0](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000025540 UIStackView:0x7fa6fc579cf0.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>",
    "<NSLayoutConstraint:0x6000000265d0 'UISV-canvas-connection' UIStackView:0x7fa6fc579cf0.leading == UIView:0x7fa6fc579e80.leading   (active)>",
    "<NSLayoutConstraint:0x600000026620 'UISV-canvas-connection' H:[MyApp.PostInteractionButton:0x7fa6fc5752d0]-(0)-|   (active, names: '|':UIStackView:0x7fa6fc579cf0 )>",
    "<NSLayoutConstraint:0x6000000266c0 'UISV-distributing-edge' H:[UIView:0x7fa6fc579e80]-(0)-[_UIOLAGapGuide:0x600001f8cd00'UISV-distributing']   (active)>",
    "<NSLayoutConstraint:0x600000026710 'UISV-distributing-edge' _UIOLAGapGuide:0x600001f8cd00'UISV-distributing'.trailing == UIView:0x7fa6fc57c3e0.leading   (active)>",
    "<NSLayoutConstraint:0x600000026800 'UISV-distributing-edge' H:[UIView:0x7fa6fc57c3e0]-(0)-[_UIOLAGapGuide:0x600001f8d300'UISV-distributing']   (active)>",
    "<NSLayoutConstraint:0x600000026850 'UISV-distributing-edge' _UIOLAGapGuide:0x600001f8d300'UISV-distributing'.trailing == UIView:0x7fa6fc57c6d0.leading   (active)>",
    "<NSLayoutConstraint:0x6000000267b0 'UISV-distributing-edge' H:[UIView:0x7fa6fc57c6d0]-(0)-[_UIOLAGapGuide:0x600001f8d400'UISV-distributing']   (active)>",
    "<NSLayoutConstraint:0x600000026940 'UISV-distributing-edge' _UIOLAGapGuide:0x600001f8d400'UISV-distributing'.trailing == MyApp.PostInteractionButton:0x7fa6fc5752d0.leading   (active)>",
    "<NSLayoutConstraint:0x6000000268a0 'UISV-fill-equally' _UIOLAGapGuide:0x600001f8d300'UISV-distributing'.width == _UIOLAGapGuide:0x600001f8cd00'UISV-distributing'.width   (active)>",
    "<NSLayoutConstraint:0x600000026990 'UISV-fill-equally' _UIOLAGapGuide:0x600001f8d400'UISV-distributing'.width == _UIOLAGapGuide:0x600001f8cd00'UISV-distributing'.width   (active)>"
)

Outro

Я действительно понятия не имею, почему существует такое поведение. Тем более, что все прекрасно работает, если я не использую эту ячейку в качестве ячейки заголовка.

Буду очень признателен за любую помощь, которую смогу получить:)

Answer 1

Мы можем включить эти ошибки в WTF Auto Layout? и получить более полное представление о том, что происходит.

Давайте начнем с первого . Здесь интересны последние 3 строки:

• Передний край View1 должен равняться переднему краю View2 плюс 16.
• Задний фронт View1 должен равняться заднему фронту View2 минус 16.
• Ширина View2 должна равняться 0.

Тем не менее, похоже, что нарушающим ограничением является ширина представления изображения, установленная на 45. UIImageView:0x7fa6fc578020.width == 45

Есть еще одно ограничение, связывающее imageView и View1 вместе: ImageView's leading edge should equal View1's leading edge.

Таким образом, с этими деталями мы можем начать формировать картину того, как это устроено.

View2LeadingEdge - 16pts - View1LeadingEdge - ImageViewLeading - 45pts - ImageViewTrailing - View1TrailingEdge - 16pts - View2Trailing

Мне кажется, что-то не так с шириной View2, равной нулю. Обратите внимание, что с каждым набором нарушающих ограничений в ошибке вы видите строку вроде:

"<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0 (active)>"

Я думаю, мне понадобится еще немного контекста для завершения отладки sh, но это должен начать вас с правой ноги. Я не уверен, что именно представляет собой View2, но я бы попытался выяснить, почему его ширина устанавливается на ноль.

Не похоже, что вы забыли отключить translatesAutoResizingMask или что ячейка автоматически добавляет это ограничение для принудительного применения макета, поэтому, если вы не можете понять это, вы также можете попробовать установить приоритет на View1's trailing edge should equal View2's trailing edge minus 16. to .defaultHigh, чтобы увидеть, может ли это помочь механизму автоматического определения местоположения определить наилучший макет

Не забудьте также проверить это:

(
    "<NSLayoutConstraint:0x600000025680 H:|-(0)-[MyApp.PostInteractionButton:0x7fa6fc5720f0](LTR)   (active, names: '|':UIView:0x7fa6fc579e80 )>",
    "<NSLayoutConstraint:0x600000025720 MyApp.PostInteractionButton:0x7fa6fc5720f0.right == MyApp.DefaultLabel:0x7fa6fc573090'1'.left - 8   (active)>",
    "<NSLayoutConstraint:0x600000025810 MyApp.DefaultLabel:0x7fa6fc573090'1'.right == UIView:0x7fa6fc579e80.right   (active)>",
    "<NSLayoutConstraint:0x600000025ef0 H:|-(16)-[UIStackView:0x7fa6fc579cf0](LTR)   (active, names: '|':UIView:0x7fa6fc56b450 )>",
    "<NSLayoutConstraint:0x600000025540 UIStackView:0x7fa6fc579cf0.right == UIView:0x7fa6fc56b450.right - 16   (active)>",
    "<NSLayoutConstraint:0x600000026fd0 UIView:0x7fa6fc56b450.width == 0   (active)>",
    "<NSLayoutConstraint:0x6000000265d0 'UISV-canvas-connection' UIStackView:0x7fa6fc579cf0.leading == UIView:0x7fa6fc579e80.leading   (active)>",
    "<NSLayoutConstraint:0x600000026620 'UISV-canvas-connection' H:[MyApp.PostInteractionButton:0x7fa6fc5752d0]-(0)-|   (active, names: '|':UIStackView:0x7fa6fc579cf0 )>",
    "<NSLayoutConstraint:0x6000000266c0 'UISV-distributing-edge' H:[UIView:0x7fa6fc579e80]-(0)-[_UIOLAGapGuide:0x600001f8cd00'UISV-distributing']   (active)>",
    "<NSLayoutConstraint:0x600000026710 'UISV-distributing-edge' _UIOLAGapGuide:0x600001f8cd00'UISV-distributing'.trailing == UIView:0x7fa6fc57c3e0.leading   (active)>",
    "<NSLayoutConstraint:0x600000026800 'UISV-distributing-edge' H:[UIView:0x7fa6fc57c3e0]-(0)-[_UIOLAGapGuide:0x600001f8d300'UISV-distributing']   (active)>",
    "<NSLayoutConstraint:0x600000026850 'UISV-distributing-edge' _UIOLAGapGuide:0x600001f8d300'UISV-distributing'.trailing == UIView:0x7fa6fc57c6d0.leading   (active)>",
    "<NSLayoutConstraint:0x6000000267b0 'UISV-distributing-edge' H:[UIView:0x7fa6fc57c6d0]-(0)-[_UIOLAGapGuide:0x600001f8d400'UISV-distributing']   (active)>",
    "<NSLayoutConstraint:0x600000026940 'UISV-distributing-edge' _UIOLAGapGuide:0x600001f8d400'UISV-distributing'.trailing == MyApp.PostInteractionButton:0x7fa6fc5752d0.leading   (active)>",
    "<NSLayoutConstraint:0x6000000268a0 'UISV-fill-equally' _UIOLAGapGuide:0x600001f8d300'UISV-distributing'.width == _UIOLAGapGuide:0x600001f8cd00'UISV-distributing'.width   (active)>",
    "<NSLayoutConstraint:0x600000026990 'UISV-fill-equally' _UIOLAGapGuide:0x600001f8d400'UISV-distributing'.width == _UIOLAGapGuide:0x600001f8cd00'UISV-distributing'.width   (active)>"
)