I have a custom document-based iOS app that also runs on macOS. After implementing -activityItemsConfiguration to enable sharing from the context menu, I found that the app crashes on macOS when selecting Share… from the context menu and then selecting Save (i.e. Save to Files under iOS). This problem does not occur on iOS, which behaves correctly. - (id<UIActivityItemsConfigurationReading>)activityItemsConfiguration { NSItemProvider * provider = [[NSItemProvider alloc] initWithContentsOfURL:self.document.presentedItemURL]; UIActivityItemsConfiguration * configuration = [UIActivityItemsConfiguration activityItemsConfigurationWithItemProviders:@[ provider ]]; // *** crashes with com.apple.share.System.SaveToFiles return configuration; } Additionally, I found that to even reach this crash, the workaround implemented in the NSItemProvider (FBxxx) category of the sample project is needed. Without this, the app will crash much earlier, due to SHKItemIsPDF() erroneously invoking -pathExtension on an NSItemProvider. This appears to be a second bug in Apple’s private ShareKit framework. #import <UniformTypeIdentifiers/UniformTypeIdentifiers.h> @implementation NSItemProvider (FBxxx) // *** SHKItemIsPDF() invokes -pathExtension on an NSItemProvider (when running under macOS, anyway) -> crash - (NSString *)pathExtension { return self.registeredContentTypes.firstObject.preferredFilenameExtension; } @end Again, this all works fine on iOS (17.5) but crashes when the exact same app build is running on macOS (14.5). I believe these bugs are Apple's. Any idea how to avoid the crash? Is there a way to disable the "Save to Files" option in the sharing popup? I filed FB13819800 with a sample project that demonstrates the crash on macOS. I was going to file a TSI to get this resolved, but I see that DTS is not responding to tech support incidents until after WWDC.

Project minimum iOS deployment is set to 16.4. When running this simple code in console we receive "Observation tracking feedback loop detected!" and map is unusable. Run code: Map(coordinateRegion: .constant(.init())) Console report: ... Observable object key path '\_UICornerProvider.<computed 0x00000001a2768bc0 (Optional<UICoordinateSpace>)>' changed; performing invalidation for [layout] of: <_TtGC7SwiftUI21UIKitPlatformViewHostGVS_P10$1a57c8f9c32PlatformViewRepresentableAdaptorGV15_MapKit_SwiftUI8_MapViewGSaVS2_P10$24ce3fc8014AnnotationData____: 0x10acc2d00; baseClass = _TtGC5UIKit22UICorePlatformViewHostGV7SwiftUIP10$1a57c8f9c32PlatformViewRepresentableAdaptorGV15_MapKit_SwiftUI8_MapViewGSaVS3_P10$24ce3fc8014AnnotationData____; frame = (0 0; 353 595); anchorPoint = (0, 0); tintColor = UIExtendedSRGBColorSpace 0.333333 0.333333 0.333333 1; layer = <CALayer: 0x12443a430>> Observable object key path '\_UICornerProvider.<computed 0x00000001a2768bc0 (Optional<UICoordinateSpace>)>' changed; performing invalidation for [layout] of: <_MapKit_SwiftUI._SwiftUIMKMapView: 0x10ae8ce00; frame = (0 0; 353 595); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x113beb7e0>> Observable object key path '\_UICornerProvider.<computed 0x00000001a2768bc0 (Optional<UICoordinateSpace>)>' changed; performing invalidation for [layout] of: <_MapKit_SwiftUI._SwiftUIMKMapView: 0x10ae8ce00; frame = (0 0; 353 595); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x113beb7e0>> Observable object key path '\_UICornerProvider.<computed 0x00000001a2768bc0 (Optional<UICoordinateSpace>)>' changed; performing invalidation for [layout] of: <_MapKit_SwiftUI._SwiftUIMKMapView: 0x10ae8ce00; frame = (0 0; 353 595); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x113beb7e0>> Observation tracking feedback loop detected! Make a symbolic breakpoint at UIObservationTrackingFeedbackLoopDetected to catch this in the debugger. Refer to the console logs for details about recent invalidations; you can also make a symbolic breakpoint at UIObservationTrackingInvalidated to catch invalidations in the debugger. Object receiving repeated [layout] invalidations: <_TtGC7SwiftUI21UIKitPlatformViewHostGVS_P10$1a57c8f9c32PlatformViewRepresentableAdaptorGV15_MapKit_SwiftUI8_MapViewGSaVS2_P10$24ce3fc8014AnnotationData____: 0x10acc2d00; baseClass = _TtGC5UIKit22UICorePlatformViewHostGV7SwiftUIP10$1a57c8f9c32PlatformViewRepresentableAdaptorGV15_MapKit_SwiftUI8_MapViewGSaVS3_P10$24ce3fc8014AnnotationData____; frame = (0 0; 353 595); anchorPoint = (0, 0); tintColor = UIExtendedSRGBColorSpace 0.333333 0.333333 0.333333 1; layer = <CALayer: 0x12443a430>> Observation tracking feedback loop detected! Make a symbolic breakpoint at UIObservationTrackingFeedbackLoopDetected to catch this in the debugger. Refer to the console logs for details about recent invalidations; you can also make a symbolic breakpoint at UIObservationTrackingInvalidated to catch invalidations in the debugger. Object receiving repeated [layout] invalidations: <_MapKit_SwiftUI._SwiftUIMKMapView: 0x10ae8ce00; frame = (0 0; 353 595); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x113beb7e0>> IDE: Xcode 26 Beta 3 Testing device: iPhone 15 Pro iOS 26 Beta 3 MacOS: Tahoe 26 Beta 3

A lot of us developers use localizeKey for localization from GUI. But in XCode16 Beta, Its not present in Storyboard or XIB. Please provide a solution in the next release.

struct ContentView: View {   @State var isPresented = false   var body: some View {     Button {       isPresented.toggle()     } label: {       Text("Button")     }     .sheet(isPresented: $isPresented) {       SubView()     }   } } struct SubView: View {   @State var text = ""   var body: some View {     NavigationStack {       TextEditor(text: $text)         .toolbar {           ToolbarItemGroup(placement: .bottomBar) {             Button("Click") {             }           }           ToolbarItemGroup(placement: .keyboard) {             Button("Click") {             }           }         }     }   } }

I am using the TabView control in SwiftUI on a tvOS 18 target with the style of sidebarAdaptable. When I have 7 or less tabs things operate correctly. When I add an 8th tab and you navigate to the contents of the tab the menu collapses as expected but you cannot navigate back to restore the menu. This code reproduces the issue: import SwiftUI struct ContentView: View { var body: some View { TabView { Tab("Tab1", systemImage: "person.circle") { Button("Button1") {} } Tab("Tab2", systemImage: "person.circle") { Button("Button2") {} } Tab("Tab3", systemImage: "person.circle") { Button("Button3") {} } Tab("Tab4", systemImage: "person.circle") { Button("Button4") {} } Tab("Tab5", systemImage: "person.circle") { Button("Button5") {} } Tab("Tab6", systemImage: "person.circle") { Button("Button6") {} } Tab("Tab7", systemImage: "person.circle") { Button("Button7") {} } Tab("Tab8", systemImage: "person.circle") { Button("Button8") {} } } .tabViewStyle(.sidebarAdaptable) } } If you eliminate Tab 8 the problem goes away. You can navigate back to the menu by moving to the left. Notably the Destination Video sample also reproduces this issue: https://developer.apple.com/documentation/visionos/destination-video To reproduce: Load the above code or Destination Video sample. Navigate right (click right on remote or swipe right). Menu dismisses and just shows the item you have selected in the upper left corner. Try to navigate left by clicking left on the remote or swiping left. It looks like the collapsed menu gets focus briefly, screen elements flash but the focus remains outside the menu. Has anyone else encountered this issue?

Hi, I am running iOS Simulator on iOS 26 and I am trying to change unselectedItemTintColor of UITabBarItem in my TabBarViewController but it did not work when I tried following ways: Setting an iconColor through UITabBarAppearance() class Setting unselected item tint color like tabBar.unselectedItemTintColor = .black As an example attached file, I would like to set Settings tab's item color (icon + title) with different one when it is unselected.

I am using AlarmKit to schedule alarms in an app I am working on, however my scheduled alarms only show up on the lock screen. If I am on the home screen or elsewhere I only hear the sound of the alarm, but no UI shows up. Environment: iOS 26 beta 3 Xcode 26 beta 3

Summary In iOS 18, the UICollectionViewDelegate method collectionView(_:targetIndexPathForMoveOfItemFromOriginalIndexPath:atCurrentIndexPath:toProposedIndexPath:) is not being called when moving items in a UICollectionView. This method works as expected in iOS 17.5 and earlier versions. Steps to Reproduce Create a UICollectionView with drag and drop enabled. Implement the UICollectionViewDelegate method: func collectionView(_ collectionView: UICollectionView, targetIndexPathForMoveOfItemFromOriginalIndexPath originalIndexPath: IndexPath, atCurrentIndexPath currentIndexPath: IndexPath, toProposedIndexPath proposedIndexPath: IndexPath) -> IndexPath { print("🐸 Move") return proposedIndexPath } Run the app on iOS 18. Attempt to drag and drop items within the collection view. Expected Behavior The method should be called during the drag and drop operation, and "🐸 Move" should be printed to the console. Actual Behavior The method is not called, and nothing is printed to the console. The drag and drop operation still occurs, but without invoking this delegate method. Configuration iOS Version: 18 Xcode Version: Xcode 16.0.0

I've been using the new template for a document-based SwiftUI app. While you get a lot of file-management "for free" in the new template, as it stands in the iOS version users have to back out of the file to the file browser to change the filename. I want to create an opportunity for the user to rename the file while it is open. Here's a sample project focused on the issue: https://github.com/stevepvc/DocumentRenamer In the code, I've added to the template code a simple UI with a textfield for the user to enter a new name. When the user hits the "rename" button, the app checks to see if the URL with that name component is available, appending a suffix if necessary to create a target url. func getTargetURL() -> URL { &#9;&#9;let baseURL&#9;=&#9;self.fileurl.deletingLastPathComponent() &#9;&#9;print("filename: \(self.filename)") &#9;&#9;print("fileURL: \(self.fileurl)") &#9;&#9;print("BaseURL: \(baseURL)") &#9;&#9;var target = URL(fileURLWithPath: baseURL.path + "/\(filename).exampletext") &#9;&#9;var nameSuffix = 1 &#9;&#9; &#9;&#9;while (target as NSURL).checkPromisedItemIsReachableAndReturnError(nil) { &#9;&#9;&#9;&#9; &#9;&#9;&#9;&#9;target = URL(fileURLWithPath: baseURL.path + "/\(filename)-\(nameSuffix).sermon") &#9;&#9;&#9;&#9;print("Checking: \(target)") &#9;&#9;&#9;&#9;nameSuffix += 1 &#9; } &#9;&#9;print("Available Target: \(target)") &#9;&#9;return target } It then attempts to rename the file, and this is when I am stuck. I have tried several methods, most recently the following: func changeFilename(){ &#9;&#9;let target&#9;= getTargetURL() &#9;&#9;var rv = URLResourceValues() &#9;&#9;let newFileName = target.deletingPathExtension().lastPathComponent &#9;&#9;rv.name = newFileName &#9;&#9;do { &#9;&#9;&#9;&#9;if fileurl.startAccessingSecurityScopedResource(){ &#9;&#9;&#9;&#9;&#9;&#9;try fileurl.setResourceValues(rv) &#9;&#9;&#9;&#9;&#9;&#9;fileurl.stopAccessingSecurityScopedResource() &#9;&#9;&#9;&#9;} &#9;&#9;} catch { &#9;&#9;&#9;&#9;print("Error:\(error)") &#9;&#9;} } But I keep getting the following error whenever I run the app on a device: Domain=NSCocoaErrorDomain Code=513 "You don’t have permission to save the file “Untitled” in the folder “DocumentRenamer”." I have also tried this without the startAccessingSecurityScopedResource() check, and alternatively have tried creating a helper class as follows: class FileMover: NSObject { func moveFile(originalURL: URL, updatedURL:URL) -> Bool { &#9;&#9;let coordinator = NSFileCoordinator(filePresenter: nil) &#9;&#9;var writingError: NSError? = nil &#9;&#9;var success : Bool = true &#9;&#9;print("moving file") &#9;&#9;coordinator.coordinate(writingItemAt: originalURL, options: NSFileCoordinator.WritingOptions.forMoving, error: &writingError, byAccessor: { (coordinatedURL) in &#9;&#9;&#9;&#9;do { &#9;&#9;&#9;&#9;&#9;&#9;try FileManager.default.moveItem(at: coordinatedURL, to: updatedURL) &#9;&#9;&#9;&#9;&#9;&#9;success = true &#9;&#9;&#9;&#9;&#9;&#9;print("file moved") &#9;&#9;&#9;&#9;&#9;&#9; &#9;&#9;&#9;&#9;} catch { &#9;&#9;&#9;&#9;&#9;&#9;print(error) &#9;&#9;&#9;&#9;&#9;&#9;success = false &#9;&#9;&#9;&#9;} &#9;&#9;}) return success &#9;&#9; } } But using this method locks up the app entirely. What is the correct method for renaming a file in the app's container, particularly using the new Swiftui Document based template?

It happens on a brand new SwiftUI Xcode project with nothing in it but the default base code. When I build and run, I get "Error creating the CFMessagePort needed to communicate with PPT." After some Googling, I know it has something to do with Performance Tools. I don't know what's causing it. I'm running 16.2 on a brand new M4 Mac mini.

Starting with iOS 26 beta, I'm encountering an intermittent crash in production builds related to Auto Layout and background threading. This crash did not occur on iOS 18 or earlier and has become reproducible only on devices running iOS 26 betas. We have already performed a thorough audit of our code: • Verified that all UIKit view hierarchy and layout mutations occur on the main thread. • Re-tested with strict logging—confirmed all remaining layout/constraint/view updates are performed on the main thread. • No third-party UI SDKs are used in the relevant flow. Despite that, the crash still occurs and always from a background thread, during internal UIKit layout commits. Fatal Exception: NSInternalInconsistencyException Modifications to the layout engine must not be performed from a background thread after it has been accessed from the main thread. 0 MyApp 0x7adbc8 FIRCLSProcessRecordAllThreads + 172 1 MyApp 0x7adfd4 FIRCLSProcessRecordAllThreads + 1208 2 MyApp 0x7bc4b4 FIRCLSHandler + 56 3 MyApp 0x7bc25c __FIRCLSExceptionRecord_block_invoke + 100 4 libdispatch.dylib 0x1b7cc _dispatch_client_callout + 16 5 libdispatch.dylib 0x118a0 _dispatch_lane_barrier_sync_invoke_and_complete + 56 6 MyApp 0x7bb1f0 FIRCLSExceptionRecord + 224 7 MyApp 0x7bbd1c FIRCLSExceptionRecordNSException + 456 8 MyApp 0x7badf4 FIRCLSTerminateHandler() + 396 9 Intercom 0x86684 IntercomSDK_sentrycrashcm_cppexception_getAPI + 308 10 libc++abi.dylib 0x11bdc std::__terminate(void (*)()) + 16 11 libc++abi.dylib 0x15314 __cxa_get_exception_ptr + 86 12 libc++abi.dylib 0x152bc __cxxabiv1::failed_throw(__cxxabiv1::__cxa_exception*) + 90 13 libobjc.A.dylib 0x3190c objc_exception_throw + 448 14 CoreAutoLayout 0x13a4 -[NSISEngine optimize] + 314 15 CoreAutoLayout 0x1734 -[NSISEngine _optimizeWithoutRebuilding] + 72 16 CoreAutoLayout 0x1404 -[NSISEngine optimize] + 96 17 CoreAutoLayout 0xee8 -[NSISEngine performPendingChangeNotifications] + 104 18 UIKitCore 0x27ac8 -[UIView(Hierarchy) layoutSubviews] + 136 19 UIKitCore 0xfe760 -[UIWindow layoutSubviews] + 68 20 UIKitCore 0x234228 -[UITextEffectsWindow layoutSubviews] + 44 21 UIKitCore 0x27674 -[UIImageView animationImages] + 912 22 UIKitCore 0x28134 -[UIView(Internal) _viewControllerToNotifyOnLayoutSubviews] + 40 23 UIKitCore 0x18c2898 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2532 24 QuartzCore 0xabd98 CA::Layer::perform_update_(CA::Layer*, CALayer*, unsigned int, CA::Transaction*) + 116 25 QuartzCore 0x8e810 CA::Layer::update_if_needed(CA::Transaction*, unsigned int, unsigned int) + 600 26 QuartzCore 0xad45c CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 200 27 QuartzCore 0x6e30c CA::Context::commit_transaction(CA::Transaction*, double, double*) + 540 28 QuartzCore 0x9afc4 CA::Transaction::commit() + 644 29 QuartzCore 0x16974c CA::Transaction::release_thread(void*) + 180 30 libsystem_pthread.dylib 0x4c28 _pthread_tsd_cleanup + 620 31 libsystem_pthread.dylib 0x4998 _pthread_exit + 84 32 libsystem_pthread.dylib 0x5e3c pthread_atfork + 54 33 libsystem_pthread.dylib 0x1440 _pthread_wqthread + 428 34 libsystem_pthread.dylib 0x8c0 start_wqthread + 8 Any ideas?

after i updated to iOS 26.0 Beta3, UIScrollEdgeElementContainerInteraction crashed: let scrollInteraction = UIScrollEdgeElementContainerInteraction() scrollInteraction.edge = .bottom scrollInteraction.scrollView = webView?.scrollView bottomBar.addInteraction(scrollInteraction) i got this crash info:unrecognized selector sent to instance: UIScrollEdgeElementContainerInteraction setEdge: and UIScrollEdgeElementContainerInteraction setScrollView

I recently started exploring the latest version of SwiftUI and came across a issue while working with TabView and NavigationStack. I downloaded Apple’s provided example code and began making changes to explore new SwiftUI changes. i added navigationtitle and toolbarBackground to first two tab. However, I noticed that the navigation bar "jumps" or resets when switching between tabs, even in their own example implementation. Here’s a simplified version of the example code I was testing: file name - WatchNowView .navigationTitle("Watch Now") .navigationBarTitleDisplayMode(.inline) .toolbarBackground(Color("AccentColor"),for: .navigationBar) file name - LibraryView .navigationTitle("Library") .navigationBarTitleDisplayMode(.inline) .toolbarBackground(Color("AccentColor"),for: .navigationBar) Here is a sample code link (provided by Apple developer document) : destination-video I have attached a gif below demonstrating this issue: Questions: Is this behavior expected in the latest version of SwiftUI, or is it a bug in the framework's handling of TabView and NavigationStack? Is this behavior expected as all tabbar item have their own nativationStack? Are there any official recommendations for maintaining seamless navigation experiences when using navigationStack and TabView? This behavior detracts from the otherwise smooth experience SwiftUI aims to provide. If anyone has encountered this issue and found a workaround, I’d greatly appreciate your insights. I hope Apple can review this problem to enhance the usability of SwiftUI. Thank you!

I Implement a 'SubscriptionStoreView' using 'groupID' into a project (iOS is targeting 17.2 and macOS is targeting 14.1).Build/run the application locally (both production and development environments will work fine), however once the application is live on the AppStore in AppStoreConnect, SubscriptionStoreView no longer shows products and only shows 'Subscription Unavailable' and 'The subscription is unavailable in the current storefront.' - this message is shown live in production for both iOS and macOS targets. There is no log messages shown in the Console that indicate anything going wrong with StoreKit 2, but I haven't made any changes to my code and noticed this first start appearing about 5 days ago. I expect the subscription store to be visible to all users and for my products to display. My application is live on both the iOS and macOS AppStores, it passed App Review and I have users who have previously been able to subscribe and use my application, I have not pushed any new changes, so something has changed in StoreKit2 which is causing unexpected behaviour and for this error message to display. As 'SubscriptionStoreView' is a view provided by Apple, I'm really not sure on the pathway forward other than going back to StoreKit1 which I really don't want to do. Is there any further error information that can be provided on what might be causing this and how I can fix it? (I have created a feedback ticket FB13658521)

Hi Community, I found an issue and wanted to ask you for confirmation... or help? (I will, if the issue persists or gets confirmed, of course file a bug report.) Context/Setup: macOS 15.5 Xcode 26 Beta 2 iPad Simulator, seems to be any, tested with "Simulator iPad Pro 11-inch (M4)" and "Simulator iPad mini (A17 Pro)" and also two physical iPads (mini and Pro) running iPadOS 26 Beta 2. Issue: In our project we are facing a runtime issue. Condensed down, when there is a storyboard with a UIToolbar (empty or with buttons) AND the project has the new UIDesignRequiresCompatibility set to true AND we run the app on an iPad (physical device or simulator)... As soon as the storyboard is loaded and about to be displayed the app crashes, console print: "UIKitCore/UICoreHostingView.swift:54: Fatal error: init(coder:) has not been implemented" Any iPhone (physical or simulator) works fine. Also with UIDesignRequiresCompatibility set to false it works everywhere including iPads. Minimum Deployment Target has between iOS 15 to 26 does has no effect on the outcome. So it seems there is an issue with UIToolbar in Storyboards with UIDesignRequiresCompatibility on iPads. Did anyone experience the same issue or can confirm it? Any idea how to solve it? Thanks a lot!

For certain contexts, I'd like to still have my .sheet() be full width even when it's at a small height. In iOS 26, the sheet is inset from the edges at small detents and expands to full width at larger detents. For example, I have a view where I have a .sheet() that has a height of about 200pts and it contains a horizontally scrolling picker that extends past the bounds of the screen. I'd like the .sheet to expand all the way to the edge when at these small detents, like it would previous to iOS 26. Is it possible to configure this? This change will break a number of existing designs :( A new ViewModifier such as enum PresentationWidth { case dynamic, fixed } func presentationWidth(_ width: PresentationWidth) -> some View would be very nice.

Hi folks, I’ve been trying to use the new .animation(_:body:) overload without success. I’m attempting to animate multiple properties of a view, each with different animations. This overload seems to be the perfect candidate to achieve that. Here's the code I'm using: struct ContentView: View { @State private var isAnimating = false var body: some View { Text("Hello World") .font(.largeTitle) .animation(.easeOut(duration: 1)) { $0.foregroundStyle(isAnimating ? .red : .blue) } .animation(.linear(duration: 10)) { $0.offset(x: isAnimating ? -100 : 0) } .onAppear { isAnimating = true } } } Pretty straightforward, but I don’t get any animations at all. Of course, I could wrap isAnimating = true in a withAnimation closure, but the WWDC session about those APIs mentions this is not needed. Furthermore, if I do that, the animations I provide in .animation(_:body:) are not being used. I’m really confused by this new API, and I’m starting to think it doesn’t work as advertised.

Hello, im getting popping / crackling sounds from my Macbook Pro (M4 2024) speakers. This happens when you do many certain tasks like click buttons or toggling switches when xcode has a simulator open and any background audio is playing, like spotify. The speakers go crazy especially when starting the simulator in xcode with music in background. Ive tried: Using blackhole, and changing audio output in the simulator app Deleting both .plist files form preferences file. "coreaudiod" trick in terminal restarting many times different xcode versions and simulators and swift files Nothing has worked. Any help?

Hello, we have weird crash in our app that mostly seems to happen right after launch. It is quite rare and so far I haven’t been able to reproduce it (the info below comes from Crashlytics). The main error message I have is this: failed to demangle witness for associated type 'Property' in conformance 'SwiftUI.StateObject<AppBlock.QuickBlockActivityViewModel>.(unknown context at $18f34e5b8).Box: DynamicPropertyBox' from mangled name ' � ��yxG' - subject type x does not conform to protocol ObservableObject And here is the stack trace: Crashed: com.apple.main-thread 0 libsystem_kernel.dylib 0x7200 __pthread_kill + 8 1 libsystem_pthread.dylib 0x71ac pthread_kill + 268 2 libsystem_c.dylib 0x20ca0 abort + 180 3 libswiftCore.dylib 0x3d7304 swift::fatalError(unsigned int, char const*, ...) + 134 4 libswiftCore.dylib 0x3d7324 swift::warningv(unsigned int, char const*, char*) + 30 5 libswiftCore.dylib 0x3ee678 swift_getAssociatedConformanceWitnessSlowImpl(swift::TargetWitnessTable<swift::InProcess>*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*, swift::TargetProtocolRequirement<swift::InProcess> const*) + 2078 6 libswiftCore.dylib 0x3ecb9c swift_getAssociatedTypeWitness + 236 7 SwiftUI 0x5b838 OUTLINED_FUNCTION_49 + 640 8 SwiftUI 0xa8d68 OUTLINED_FUNCTION_513 + 16260 9 SwiftUI 0x58244 OUTLINED_FUNCTION_177 + 10892 10 SwiftUI 0x95524 OUTLINED_FUNCTION_1160 + 6632 We are using the view model (QuickBlockActivityViewModel) in a SwiftUI view that is part of collection view using the new UIHostingConfiguration from iOS 16. Our view model is a subclass of view model for older iOS versions that conforms to ObservableObject and is marked as @MainActor. And the view model is used like this: @StateObject private var viewModel = QuickBlockActivityViewModel() Internally the view model uses Combine to monitor a couple of states from other parts of the app to modify its properties.

Hello! I've been digging into this for a little bit now, and am hitting something of a wall. Our app is crashing occasionally, and googling the crash yields literally 0 results. Tl;dr: Something related to adaptivePresentationStyle(for:traitCollection:) is resulting in our app crashing. Context In our app, we have a custom UIPresentationController that we use to present a small sheet of content overlaying other app content - similar to a UISheetPresentationController with a medium-ish size. So we have a custom UIViewController to present, and it conforms to the UIAdaptivePresentationControllerDelegate protocol. We also have custom present and dismiss animators. The crash However, we seem to be running into a really odd crash. I've attached a crash report as well, but here's what one sees in xcode on reproducing the crash: The _computeToEndFrameForCurrentTransition block is nil inside the _transitionViewForCurrentTransition block, value of outerStrongSelf currently : <XxxYyyyyyZzz.PopupPresentationController: 0x12d017a40>. This most likely indicates that an adaptation is happening after a transtion cleared out _computeToEndFrameForCurrentTransition. Captured debug information outside block: presentationController : <XxxYyyyyyZzz.PopupPresentationController: 0x12d017a40> presentedViewController : <XxxYyyyyyZzz.SomeViewController: 0x12d03a690> presentingViewController : <UINavigationController: 0x12a817400> 2023-09-25_08-02-33.6523_-0500-7d355cd4a86427213389765ef070a777c4b4aaa3.crash Whenever we present one of these view controllers, things work just fine. When we try to present another one though, if someone is aggressively changing the phone orientation, the app crashes. This crash occurs somewhere in between dismissing the old VC and presenting the new one. It occurs before I ever hit any breakpoints in the "present" animator for the second view controller. I've narrowed things down a bit, and by commenting out our implementation of adaptivePresentationStyle(for:traitCollection:), the crash can't be reproduced anymore. The downside there being that the app no longer functions how we want it to. Our definition of that function (which causes crashes) looks like this: public func adaptivePresentationStyle(for controller: UIPresentationController, traitCollection: UITraitCollection) -> UIModalPresentationStyle { guard forceUsingFullScreenIfCompact else { return .none } return traitCollection.verticalSizeClass == .compact ? .overFullScreen : .none } A bit more testing, and it seems like if that function returns the same thing consistently, nothing crashes. Are we not allowed to put conditional logic in this function? In the crash, we can see that it occurs due to a failing assertion internal to UIPresentationController: Last Exception Backtrace: 0 CoreFoundation 0x1afa28cb4 __exceptionPreprocess + 164 (NSException.m:202) 1 libobjc.A.dylib 0x1a8abc3d0 objc_exception_throw + 60 (objc-exception.mm:356) 2 Foundation 0x1aa1b2688 -[NSAssertionHandler handleFailureInFunction:file:lineNumber:description:] + 172 (NSException.m:251) 3 UIKitCore 0x1b1d05610 __80-[UIPresentationController _initViewHierarchyForPresentationSuperview:inWindow:]_block_invoke + 2588 (UIPresentationController.m:1594) 4 UIKitCore 0x1b21f1ff4 __56-[UIPresentationController runTransitionForCurrentState]_block_invoke_3 + 300 (UIPresentationController.m:1228) The question This all leads us to wonder if we're doing something wrong, or if there could be a bug in one of the iOS APIs that we're consuming. Thus, posting here. Does anyone have any insight into how this could be occurring, or has seen this before and has ideas? Thanks! Miscellaneous info We target iOS 14+ We've seen this issue in debug and release builds from Xcode 14 and 15 We see the issue on users with iOS 15+, though it could be occurring on 14 in just incredibly low numbers This is a re-post of https://developer.apple.com/forums/thread/738257, because I accidentally closed that out as resolved