The speaker mentions there is "less risk of creating a retain cycle in when capturing self in a closure within a value type", such as a SwiftUI view struct. Can you elaborate on when this could actually occur? Thanks!

Hello, everyone! Help me please to find answer. I have two applications: App-1 with share extension and App-2 without it. From the second app I can open share extension via UIActivityViewController. But I need this extension in the second application to open immediately by pressing a button, and not through UIActivityViewController. Can I do this?

We are getting a crash _dispatch_assert_queue_fail when the cancellationHandler on NSProgress is called. We do not see this with iOS 17.x, only on iOS 18. We are building in Swift 6 language mode and do not have any compiler warnings. We have a type whose init looks something like this: init( request: URLRequest, destinationURL: URL, session: URLSession ) { progress = Progress() progress.kind = .file progress.fileOperationKind = .downloading progress.fileURL = destinationURL progress.pausingHandler = { [weak self] in self?.setIsPaused(true) } progress.resumingHandler = { [weak self] in self?.setIsPaused(false) } progress.cancellationHandler = { [weak self] in self?.cancel() } When the progress is cancelled, and the cancellation handler is invoked. We get the crash. The crash is not reproducible 100% of the time, but it happens significantly often. Especially after cleaning and rebuilding and running our tests. * thread #4, queue = 'com.apple.root.default-qos', stop reason = EXC_BREAKPOINT (code=1, subcode=0x18017b0e8) * frame #0: 0x000000018017b0e8 libdispatch.dylib`_dispatch_assert_queue_fail + 116 frame #1: 0x000000018017b074 libdispatch.dylib`dispatch_assert_queue + 188 frame #2: 0x00000002444c63e0 libswift_Concurrency.dylib`swift_task_isCurrentExecutorImpl(swift::SerialExecutorRef) + 284 frame #3: 0x000000010b80bd84 MyTests`closure #3 in MyController.init() at MyController.swift:0 frame #4: 0x000000010b80bb04 MyTests`thunk for @escaping @callee_guaranteed @Sendable () -> () at <compiler-generated>:0 frame #5: 0x00000001810276b0 Foundation`__20-[NSProgress cancel]_block_invoke_3 + 28 frame #6: 0x00000001801774ec libdispatch.dylib`_dispatch_call_block_and_release + 24 frame #7: 0x0000000180178de0 libdispatch.dylib`_dispatch_client_callout + 16 frame #8: 0x000000018018b7dc libdispatch.dylib`_dispatch_root_queue_drain + 1072 frame #9: 0x000000018018bf60 libdispatch.dylib`_dispatch_worker_thread2 + 232 frame #10: 0x00000001012a77d8 libsystem_pthread.dylib`_pthread_wqthread + 224 Any thoughts on why this is crashing and what we can do to work-around it? I have not been able to extract our code into a simple reproducible case yet. And I mostly see it when running our code in a testing environment (XCTest). Although I have been able to reproduce it running an app a few times, it's just less common.

Is it ok for an Actor type to have a Publisher as a property to let others observe changes over time? Or use the @Published property wrapper to achieve this? actor MyActor { var publisher = PassthroughSubject<Int, Never>() var data: Int { didSet { publisher.send(data) } } ... } // Usage var tasks = Set<AnyCancellable>() let actor = MyActor() Task { let publisher = await actor.publisher publisher.sink { print($0) }.store(in: &tasks) } This seems like this should be acceptable. I would expect a Publisher to be thread safe, and as long as the Output is a value type things should be fine. I have been getting random EXC_BAD_ACCESS errors when using this approach. But turning on the address sanitizer causes these crashes to go away. I know that isn't very specific but I wanted to start by seeing if this type of pattern is ok to do.

We started building our project in XCode 16 only to find a super weird crash that was 100% reproducible. I couldn't really understand why it was crashing, so I tried to trim down the problematic piece of code to something that I could provide in a side project. The actual piece of code crashing for us is significantly different, but this small example showcases the crash as well. https://github.com/Elih96/XCode16CrashReproducer our observation is, that this combination of async let usage + struct structure leads to a SIGABRT crash in the concurrency library. In both the main project and the example project, moving away from async let and using any other concurrency mechanism fixes the crash. This was reproducible only on Xcode 16 with iOS 15 set as minimum deployment for the target. It works fine on Xcode 15, and if we bump the min deployment to 16 on Xcode 16, it also runs fine. I've attached a small project that reproduces the error. I'm sure I didn't provide the ideal reproduction scenario, but that's what I managed to trim it down to. Making random changes such as removing some properties from the B struct or remove the: let _ = A().arrayItems.map { _ in "123" } will stop the crash from happening, so I just stopped making changes. The stack trace from the crash: frame #0: 0x00000001036d1008 libsystem_kernel.dylib`__pthread_kill + 8 frame #1: 0x0000000102ecf408 libsystem_pthread.dylib`pthread_kill + 256 frame #2: 0x00000001801655c0 libsystem_c.dylib`abort + 104 frame #3: 0x000000020a8b7de0 libswift_Concurrency.dylib`swift::swift_Concurrency_fatalErrorv(unsigned int, char const*, char*) + 28 frame #4: 0x000000020a8b7dfc libswift_Concurrency.dylib`swift::swift_Concurrency_fatalError(unsigned int, char const*, ...) + 28 frame #5: 0x000000020a8baf54 libswift_Concurrency.dylib`swift_task_dealloc + 124 frame #6: 0x000000020a8b72c8 libswift_Concurrency.dylib`asyncLet_finish_after_task_completion(swift::AsyncContext*, swift::AsyncLet*, void (swift::AsyncContext* swift_async_context) swiftasynccall*, swift::AsyncContext*, void*) + 72 * frame #7: 0x000000010344e6e4 CrashReproducer.debug.dylib`closure #1 in closure #1 in CrashReproducerApp.body.getter at CrashReproducerApp.swift:17:46 frame #8: 0x00000001cca0a560 SwiftUI`___lldb_unnamed_symbol158883 frame #9: 0x00000001cca09fc0 SwiftUI`___lldb_unnamed_symbol158825 frame #10: 0x00000001cca063a0 SwiftUI`___lldb_unnamed_symbol158636 frame #11: 0x00000001cca09268 SwiftUI`___lldb_unnamed_symbol158726

I have a workspace with my project and a Swift Macro. When I use the "Build Documentation" command the build fails with this error: fatal error: module map file '/Users/me/Library/Developer/Xcode/DerivedData/Project-fmdkuqlofexbqdhhitpgjnoqzyrz/Build/Intermediates.noindex/GeneratedModuleMaps-iphoneos/Macros.modulemap' not found Is there a way around this?

I have a Package.swift // swift-tools-version: 5.9 // The swift-tools-version declares the minimum version of Swift required to build this package. import PackageDescription let package = Package( name: "SharedUI", defaultLocalization: "en_US", platforms: [.iOS(.v16)], products: [ .library( name: "SharedUI", targets: [ "AppTheme", ] ), ], dependencies: [ .package(url: "https://github.com/apple/swift-markdown.git", "0.2.0"..<"0.3.0"), ], targets: [ .target( name: "AppTheme", dependencies: [ .product(name: "Markdown", package: "swift-markdown"), ], path: "AppTheme" ), ] ) Run swift package show-dependencies shows error yuantong-macbookpro2:Downloads yuantong$ swift package show-dependencies Fetching https://github.com/apple/swift-markdown.git from cache Fetched https://github.com/apple/swift-markdown.git (0.67s) error: Couldn’t get the list of tags: fatal: cannot use bare repository '/Users/yuantong/Downloads/.build/repositories/swift-markdown-b692ce3c' (safe.bareRepository is 'explicit') which I think used to work before Xcode 15.

Recently I updated to Xcode 14.0. I am building an iOS app to convert recorded audio into text. I got an exception while testing the application from the simulator(iOS 16.0). [SpeechFramework] -[SFSpeechRecognitionTask handleSpeechRecognitionDidFailWithError:]_block_invoke Ignoring subsequent recongition error: Error Domain=kAFAssistantErrorDomain Code=1101 "(null)" Error Domain=kAFAssistantErrorDomain Code=1107 "(null)" I have to know what does the error code means and why this error occurred.

Hey all! During the migration of a production app to swift 6, I've encountered a problem: when hitting the UNUserNotificationCenter.current().requestAuthorization the app crashes. If I switch back to Language Version 5 the app works as expected. The offending code is defined here class AppDelegate: NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -&gt; Bool { FirebaseApp.configure() FirebaseConfiguration.shared.setLoggerLevel(.min) UNUserNotificationCenter.current().delegate = self let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound] UNUserNotificationCenter.current().requestAuthorization(options: authOptions) { _, _ in } application.registerForRemoteNotifications() Messaging.messaging().delegate = self return true } } The error is depicted here: I have no idea how to fix this. Any help will be really appreciated thanks in advance

Getting this error several times when presenting a modal window over my splitview window when running it on my Mac using Swift/Mac Catalyst in XCode 14.2. When I click the Cancel button in the window then I get Scene destruction request failed with error: (null) right after an unwind segue. 2023-07-04 16:50:45.488538-0500 Recipes[27836:1295134] [WindowHosting] UIScene property of UINSSceneViewController was accessed before it was set. 2023-07-04 16:50:45.488972-0500 Recipes[27836:1295134] [WindowHosting] UIScene property of UINSSceneViewController was accessed before it was set. 2023-07-04 16:50:45.496702-0500 Recipes[27836:1295134] [WindowHosting] UIScene property of UINSSceneViewController was accessed before it was set. 2023-07-04 16:50:45.496800-0500 Recipes[27836:1295134] [WindowHosting] UIScene property of UINSSceneViewController was accessed before it was set. 2023-07-04 16:50:45.994147-0500 Recipes[27836:1295134] Unbalanced calls to begin/end appearance transitions for <UINavigationController: 0x7f7fdf068a00>. bleep 2023-07-04 16:51:00.655233-0500 Recipes[27836:1297298] Scene destruction request failed with error: (null) I don't quite understand what all all this means. (The "bleep" was a debugging print code I put in the unwind segue). I'm working through Apple's Mac Catalyst tutorial but it seems to be riddled with bugs and coding issues, even in the final part of the completed app which I dowmloaded and ran. I don't see these problems on IPad simulator. I don't know if it's because Catalyst has problems itself or there's something else going on that I can fix myself. Any insight into these errors would be very much appreciated! PS: The app seems to run ok on Mac without crashing despite the muliple issues

Hello, I have a problem with the .onMove function. I believe I have set everything up properly. However, the moving does not seem to be working correctly. When I try to move the item, it is highlighted first, as it is supposed to be. Then, while I am moving it through the list, it disappears for some reason, and at the end of the move, it comes back to its initial place. (I use iOS 16.0 minimum, so I don't have to include the EditButton(). It works the same in the edit mode tho) import SwiftUI struct Animal: Identifiable { var id = UUID() var name: String } struct ListMove: View { @State var animals = [Animal(name: "Dog"), Animal(name: "Cat"), Animal(name: "Cow"), Animal(name: "Goat"), Animal(name: "Chicken")] var body: some View { List { ForEach(animals) { animal in Text(animal.name) } .onMove(perform: move) } } func move(from source: IndexSet, to destination: Int) { animals.move(fromOffsets: source, toOffset: destination) } } #Preview { ListMove() }

Is there any way to use metal-cpp in a Swift project? I have a platform layer I've written in Swift that handles Window/View creation, as well as event handling, etc. I've been trying to bridge this layer with my C++ layer as you normally would using a pure C interface, but using Metal instances that cross this boundary just doesn't seem to work. e.g. Currently I initialize a CAMetalLayer for my NSView, setting that as the layer for the view. I've tried passing this Metal layer into my C++ code via a void* pointer through a C interface, and then casting it to a CA::MetalView to be used. When this didn't work, I tried creating the CA::MetalLayer in C++ and passing that back to the Swift layer as a void* pointer, then binding it to a CAMetalLayer type. And of course, this didn't work either. So are the options for metal-cpp to use either Objective-C or just pure C++ (using AppKit.hpp)? Or am I missing something for how to integrate with Swift?

A program I wrote in Swift that uploads and downloads to a private database in iCloud is failing for downloads since the the 15.2 update. It still works for uploads. I.e., I can download uploads made from the program under 15.2 on another computer running the same program under 15.1 The Fetch operation does not return an error, but the returnRecord is empty! I do get the error below after the fact of the failure, don't know if it's related. "ViewBridge to RemoteViewService Terminated: Error Domain=com.apple.ViewBridge Code=18 "(null)" UserInfo={com.apple.ViewBridge.error.hint=this process disconnected remote view controller -- benign unless unexpected, com.apple.ViewBridge.error.description=NSViewBridgeErrorCanceled}" To be clear, I assume I do have access to the database since it works for upload under 15.2, as well as upload and download under 15.1, and from a very similar program on my iPhone (which I haven't updated yet!) Questions? Comments? Thanks!

For my app I was trying to write some tests to ensure the functionality of all features. As I am using Xcode 16.0 I thought I might use Swift testing which was newly introduced and replaces XCTest. I created a new test target with Swift Testing and tried to run the first test, which was created automatically by the system. struct FinancialTests { @Test func testExample() async throws { #expect(true) } } Xcode is also showing the test diamond next to the function so I clicked on it to execute it. The app started to build and the build ended successfully. The the next step was testing. And after waiting for 10 minutes or so, no test was executed. First I thought maybe the test was not found, but in the test case overview all tests were shown: The run only shows this: Can someone help me to get this running. Many thanks!

This is not a question but more of a hint where I was having trouble with. In my SwiftData App I wanted to move from Swift 5 to Swift 6, for that, as recommended, I stayed in Swift 5 language mode and set 'Strict Concurrency Checking' to 'Complete' within my build settings. It marked all the places where I was using predicates with the following warning: Type '' does not conform to the 'Sendable' protocol; this is an error in the Swift 6 language mode I had the same warnings for SortDescriptors. I spend quite some time searching the web and wrapping my head around how to solve that issue to be able to move to Swift 6. In the end I found this existing issue in the repository of the Swift Language https://github.com/swiftlang/swift/issues/68943. It says that this is not a warning that should be seen by the developer and in fact when turning Swift 6 language mode on those issues are not marked as errors. So if anyone is encountering this when trying to fix all issues while staying in Swift 5 language mode, ignore those, fix the other issues and turn on Swift 6 language mode and hopefully they are gone.

Hi, I’m trying to use the new InlineArray type, but noticed that it is unfortunately only available on macOS 26 and not on macOS 15 and others. As this is quite an essential type, I was wondering if this is intended or will this change in later beta’s? Not having it available on older Darwin platforms would severily limit it’s usage in the coming years. Thanks!

This is one of the worst errors you can encounter while developing with Xcode. It looks like it's related to a problem inside the compiler itself: when there are lot of lines of code, it becomes unable to identify them all and start asking you to break down the code in smaller pieces. Sometimes you can, sometimes not. First of all, in your code there is FOR SURE an error, so in case of the second option, begin commenting entires sections of your code: this can lead to two options: You commented a section that contains the error: Xcode give you the preview and you check the commented section to find the error You commented enough code to let the compiler do its job, and you'll have the normal error reported in your code: again, fix it! Once errors have been fixed, normally you can uncomment what you excluded and all will go up and ok again. The most common errors that can lead to this behavior (but it's just a hint) are those involving parameters got or passed to other SwiftUI objects: parameters label (mistyped, missing, exceeding) parameters values (not $/& present, $/& present but not required) parameters types (you passed a wrong type) Well, I hope that this post could be useful to others that, like I did, are struggling a lot to understand the exact nature of this peculiar error. Code well and Prosper!

I am using Xcode 15 and working on a localised app. I use the new String Catalogs feature which works great for my app. In my app I created some local package like Apple has done it in the Backyard Birds example. However the translations I did in the package's String Catalog won’t be used in the app. What am I doing wrong?

Crash Log We have a issue with our watch app. When we do a release build with xcode 16 the watch app will not launch and crashes on watchOS 10 and below devices. It does not do this on debug builds...and it does not do this on xcode 15 release/debug builds. Anybody running into watch crashes on xcode 16? Thanks

Hello everyone. macOS, IOBluetooth framework. My goal is to create a temporary SDP service. According to the documentation, by default a temporary service is created (aka Persistent = NO), which is deleted after the application is closed. The documentation also mentions the IOBluetoothRemoveServiceWithRecordHandle function for forced removal of the service. This function is deprecated and is currently unavailable. I guesse that it has been replaced by the IOBluetoothSDPServiceRecord.removeServiceRecord method. The essence of the problem is that the server is not deleted either using removeServiceRecord or even after app closing. That is, if you create several services and try to delete them, they will remain alive. Only turning Bluetooth off and on in the OS helps. I tested all versions of macOS starting with Monteray. The same behavior. for (int i = 0; i < 10; i++) { service = [IOBluetoothSDPServiceRecord publishedServiceRecordWithDictionary:dictionary]; if (!service) { NSLog(@"Failed to create service"); } else { [service getRFCOMMChannelID:&channelID]; [service getServiceRecordHandle:&serverHandle]; NSLog(@"A new service has been created handle=%u, channelID=%hhu", serverHandle, channelID); if (service.removeServiceRecord != kIOReturnSuccess) { NSLog(@"Failed to delete service"); } //service.release; service = nil; } } Can someone confirm this behavior? And is there a solution? A minimal test example is available at the link