Crash on rive::gpu::BackgroundShaderCompiler::threadMain() when used in UIBarButtonItem

[alecsmirnov]

Hello!

Description

Rive, for some reason, crashed (SIGABRT (ABORT)) several times during runtime before showing the animation when used in UIBarButtonItem.

Simplified code

// View and VM, which are used as a container for RiveView to change visibility
// final class AnimatedViewModel: RiveViewModel { ... }

final class AnimatedView: UIView {
    var viewModel: AnimatedViewModel? {
        didSet {
            viewModel?.setView(riveView)

            viewModel.configureStateChangeAction { [weak self] isHidden in
                self?.riveView.isHidden = isHidden
            }
        }
    }

    private let riveView = RiveView()

    init() {
        super.init(frame: .zero)

        addSubview(riveView)
        riveView.translatesAutoresizingMaskIntoConstraints = false
        
        riveView.topAnchor.constraint(equalTo: topAnchor).isActive = true
        riveView.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
        riveView.leftAnchor.constraint(equalTo: leftAnchor).isActive = true
        riveView.rightAnchor.constraint(equalTo: rightAnchor).isActive = true
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

// Custom UIBarButtonItem for adding AnimatedView and interactions with it
final class AnimatedBarButtonItem: UIBarButtonItem {
    var viewModel: AnimatedBarButtonItemViewModel? {
        didSet {
            animatedView.viewModel = viewModel?.animatedViewModel

            viewModel.configure(tapRecognizer: tapRecognizer)
            viewModel?.configureTapRecognizerAvailabilityAction { [weak self] isEnabled in
                self?.tapRecognizer.isEnabled = isEnabled
            }
        }
    }

    private let animatedView = AnimatedView()
    private let tapRecognizer = UITapGestureRecognizer()

    override public init() {
        super.init()

        animatedView.addGestureRecognizer(tapRecognizer)

        customView = animatedView
        customView?.translatesAutoresizingMaskIntoConstraints = false
        customView?.widthAnchor.constraint(equalToConstant: 60).isActive = true
        customView?.heightAnchor.constraint(equalToConstant: 50).isActive = true
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

// Add this button to the navbar in VC
final class MainViewController: UIViewController {
    ...
    
    func configureNavigationBar() {
        navigationItem.rightBarButtonItems = [AnimatedBarButtonItem()]
    }
}

Crash Report

Crashed: Thread #1
SIGABRT ABORT 0x00000001db4e12d4

          Crashed: Thread
0  libsystem_kernel.dylib         0xc2d4 __pthread_kill + 8
1  libsystem_pthread.dylib        0x859c pthread_kill + 268
2  libsystem_c.dylib              0x77b08 abort + 128
3  RiveRuntime                    0x1a95f4 rive::gpu::BackgroundShaderCompiler::threadMain() + 2492
4  RiveRuntime                    0x1a9768 void* std::__1::__thread_proxy[abi:un170006]<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct>>, void (rive::gpu::BackgroundShaderCompiler::*)(), rive::gpu::BackgroundShaderCompiler*>>(void*) + 72
5  libsystem_pthread.dylib        0x17d0 _pthread_start + 136
6  libsystem_pthread.dylib        0x1480 thread_start + 8

Expected behavior

The application should not crash.

Device & Versions (please complete the following information)

• Device: iPhone SE (2nd generation), iPhone 14
• iOS version iOS 16, iOS 18.2
• Rive version: 6.0.7

Additional context

The crash is very rare, but it appears from time to time and only on real devices, and the reason is still unclear.

[dskuza]

Have you tried any of the latest versions of the runtime? I'm curious if the problem still exists (we've had a few minor releases since v6.0.7).

[alecsmirnov]

I'll try the latest version and try to check. Thanks.