UINavigationController subclass crashes

[abear247]

The crash

objc[75872]: Cannot form weak reference to instance (0x14f032000) of class Top_Hat.TestNav. It is possible that this object was over-released, or is in the process of deallocation.

Crash log from our setup.

Digging into it we found that the simplest reproducible was

class TestNav: UINavigationController {}

// triggered from a button
func buttonPressed() {
    let hostingViewController = UIHostingController(rootView: EmptyView())
    let navigationController = TestNav(rootViewController: hostingViewController)
    present(navigationController, animated: true)
}

This was caught during QA when we were trying to add in Datadog RUM.

RUM setup code

    private func initializeDatadog(config: Config) {
        let ddConfig = Datadog.Configuration.builderUsing(
            rumApplicationID: config.rumApplicationID,
            clientToken: config.clientToken,
            environment: config.environment
        )
        .set(serviceName: config.serviceName)
        .set(endpoint: .us1)
        .trackUIKitRUMViews()
        .trackUIKitRUMActions()
        .enableTracing(true)
        .build()

        Datadog.initialize(
            appContext: .init(), trackingConsent: .granted, configuration: ddConfig
        )
        Global.rum = RUMMonitor.initialize()
    }

There is a workaround that does not crash. So this seems particularly related to the default predicate.

class CustomPredicate: UIKitRUMViewsPredicate {
    func rumView(for viewController: UIViewController) -> RUMView? {
        return .init(name: "\(type(of: viewController))")
    }
}

Datadog SDK versions:

1.20.0

Last stable Datadog SDK version:

None, we haven't shipped this yet

Volume:

Easily reproducible within <5 swipes to close presented view

OS version:

iOS 16.2

Deployment Target:

14.0, iPhone and iPad

Device version:

iPhone 11

Environment:

N/A

[ncreated]

Hello @abear247 👋. I confirm, we can reproduce the problem and we added it to our backlog. Stay tuned for updates.

💡 Regarding mitigation (nice you discovered it ⭐), you can make it more specific by only applying it to the modal view controller and forwarding all other calls to our default predicate.

PS. Thanks a million for perfect information and isolating the reproduction steps to bare minimum. That helps a lot!

[ncreated]

This problem was fixed in #1533 and deployed in 2.5.0. I'm closing this issue.