func oneStepForward(_ input: Int) -> Int { return input + 1 } func oneStepBackward(_ input: Int) -> Int { return input - 1 } func chooseStepFunction(backward: Bool) -> (Int) -> Int { return backward ? oneStepBackward : oneStepForward //Error. type of expression is ambiguous without a type annotation } Why am I getting this error ? If I change this function to the following it works and will compile. func chooseStepFunction(backward: Bool) -> (Int) -> Int { if backward { return oneStepBackward } else { return oneStepForward } } // Why am I getting the error in the previous version while it works in the second version ? Thx in advance.

I filed the following issue on swiftlang/swift on GitHub (Aug 8th), and a followup the swift.org forums, but not getting any replies. As we near the release of Swift 6.2, I want to know if what I'm seeing below is expected, or if it's another case where the compiler needs a fix. protocol P1: Equatable { } struct S1: P1 { } // Error: Conformance of 'S1' to protocol 'P1' crosses into main actor-isolated code an can cause data races struct S1Workaround: @MainActor P1 { } // OK // Another potential workaround if `Equatable` conformance can be moved to the conforming type. protocol P2 { } struct S2: Equatable, P2 { } // OK There was a prior compiler bug fix which addressed inhereted protocols regarding @MainActor. For Equatable, one still has to use @MainActoreven when the default actor isolation is MainActor. Also affects Hashable and any other protocol inheriting from Equatable.

Hello, While watching WWDC25: Code-along: Elevate an app with Swift concurrency at timestamp 25:48, I noticed something in the slide/diagram that might be incorrect. The diagram shows ExtractSticker twice, but based on the code context and spoken explanation, I think it was meant to be ExtractSticker and ExtractColor. Reasoning: The surrounding code and narration describe the use of async let and a Sendable Data object. From the flow, one task extracts a sticker while the other extracts a color, so it seems like the diagram is inconsistent. I do understand that with @concurrent, having two ExtractSticker operations on the same Data is technically possible (with two concurrent process executing their respective ExtractSticker) — but that would be a different meaning than what the talk was describing. Since concurrency is already a subtle and error-prone topic, I thought it was worth pointing this out. If I’m mistaken, I’d love clarification. Otherwise, this could be a small correction to keep things aligned and clearer for everyone. Minor point overall, but Swift 6’s concurrency model is doing a fantastic job at helping us write safer code—so thank you to the team for that! (Attaching screenshots for reference)

I’m stuck with repeated production crashes in my SwiftUI app and I can’t make sense of the traces on my own. The symbolicated reports show the same pattern: Crash on com.apple.CFNetwork.LoaderQ with EXC_BAD_ACCESS / PAC failure Always deep in CFNetwork, most often in URLConnectionLoader::loadWithWhatToDo(NSURLRequest*, _CFCachedURLResponse const*, long, URLConnectionLoader::WhatToDo) No frames from my code, no sign of AuthManager or tokens. What I’ve tried: Enabled Address Sanitizer, Malloc Scribble, Guard Malloc, Zombies. Set CFNETWORK_DIAGNOSTICS=3 and collected Console logs. Stress-tested the app (rapid typing, filter switching, background/foreground, poor network with Network Link Conditioner). Could not reproduce the crash locally. So far: Logs show unrelated performance faults (I/O on main thread, CLLocationManager delegate), but no obvious CFNetwork misuse. My suspicion is a URLSession lifetime or delegate/auth-challenge race, but I can’t confirm because I can’t trigger it. Since starting this investigation, I also refactored some of my singletons into @State/@ObservedObject dependencies. For example, my app root now wires up AuthManager, BackendService, and AccountManager (where API calls happen using async/await) as @State properties: @State var authManager: AuthManager @State var accountManager: AccountManager @State var backendService: BackendService init() { let authManager = AuthManager() self._authManager = .init(wrappedValue: authManager) let backendService = BackendService(authManager: authManager) self._backendService = .init(wrappedValue: backendService) self._accountManager = .init(wrappedValue: AccountManager(backendService: backendService)) } I don’t know if this refactor is related to the crash, but I am including it to be complete. Apologies that I don’t have a minimized sample project — this issue seems app-wide, and all I have are the crash logs. Request: Given the crash location (URLConnectionLoader::loadWithWhatToDo), can Apple provide guidance on known scenarios or misuses that can lead to this crash? Is there a way to get more actionable diagnostics from CFNetwork beyond CFNETWORK_DIAGNOSTICS to pinpoint whether it’s session lifetime, cached response corruption, or auth/redirect? Can you also confirm whether my dependency setup above could contribute to URLSession or backend lifetime issues? I can’t reliably reproduce the crash, and without Apple’s insight the stack trace is effectively opaque to me. Thanks for your time and help. Happy to send multiple symbolicated crash logs at request. Thanks for any help. PS. Including 2 of many similar crash logs. Can provide more if needed. Atlans-2025-07-29-154915_symbolicated (cfloader).txt Atlans-2025-08-08-124226_symbolicated (cfloader).txt

Hello I want to implement customisation to swift argumentparser, Here are following changes want to do it in my cli changing default footer present in help command output currently help command output coming like this OVERVIEW: clisample USAGE: clisample <subcommand> OPTIONS: --version show the version. -h, --help show the help. SUBCOMMANDS: logs (default) Export logs for clisample processes. See 'clisample --help' for more information.' so instead of See 'clisample --help' for more information.' I want my own string For more details, run 'clisample help <subcommand>' customise error string getting from validation error Error: Missing value for '-t <time>' Help: -t <time> Time window (e.g. 10h, 30m, 2d). Usage: clisample logs --time <time> See 'clisample logs --help' for more information. so I want error output with example and customised footer, like this Error: Missing value for '-t <time>' Help: -t <time> Time window (e.g. 10h, 30m, 2d). Usage: clisample logs --time <time> Example: clisample logs -t 5m For more details, run 'clisample help <subcommand>' Is this changes possible from anyway?

Undefined symbols for architecture arm64: "_swift_coroFrameAlloc", referenced from: NvMobileCore.Constraint.isActive.modify : Swift.Bool in NvMobileCore[5] NvMobileCore.Constraint.isActive.modify : Swift.Bool in NvMobileCore[5] NvMobileCore.NvMobileCoreManager.delegate.modify : NvMobileCore.NvPublicInterface? in NvMobileCore[53] NvMobileCore.NvMobileCoreManager.delegate.modify : NvMobileCore.NvPublicInterface? in NvMobileCore[53] NvMobileCore.NvMobileCoreManager.language.modify : Swift.String in NvMobileCore[53] NvMobileCore.NvMobileCoreManager.language.modify : Swift.String in NvMobileCore[53] ld: symbol(s) not found for architecture arm64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

Xcode downloaded a crash report for my app that crashed when trying to insert a String into a Set<String>. Apparently there was an assertion failure ELEMENT_TYPE_OF_SET_VIOLATES_HASHABLE_REQUIREMENTS. I assume that this assertion failure happened because the hash of the new element didn't match the hash of an equal already inserted element, but regardless, I don't understand how inserting a simple string could trigger this assertion. Here is essentially the code that leads to the crash. path is any file system directory, and basePath is a directory higher in the hierarchy, or path itself. var scanErrorPaths = Set<String>() func main() { let path = "/path/to/directory" let basePath = "/path" let fileDescriptor = open(path, O_RDONLY) if fileDescriptor < 0 { if (try? URL(fileURLWithPath: path, isDirectory: false).checkResourceIsReachable()) == true { scanErrorPaths.insert(path.relativePath(from: basePath)!) return } } extension String { func relativePath(from basePath: String) -> String? { if basePath == "" { return self } guard let index = range(of: basePath, options: .anchored)?.upperBound else { return nil } return if index == endIndex || basePath == "/" { String(self[index...]) } else if let index = self[index...].range(of: "/", options: .anchored)?.upperBound { String(self[index...]) } else { nil } } } crash.crash

Error: "Attrubute can only be applied to types not declarations" on line 2 : @unchecked @unchecked enum ReminderRow : Hashable, Sendable { case date case notes case time case title var imageName : String? { switch self { case .date: return "calendar.circle" case .notes: return "square.and.pencil" case .time: return "clock" default : return nil } } var image : UIImage? { guard let imageName else { return nil } let configuration = UIImage.SymbolConfiguration(textStyle: .headline) return UIImage(systemName: imageName, withConfiguration: configuration) } var textStyle : UIFont.TextStyle { switch self { case .title : return .headline default : return .subheadline } } }

I have c++ macOs app(Xcode +14) and I try to add call to swift code. I can't find any simple c++ xcodeproj call to swift code. I create new simple project and fail to build it with error when I try to include #include <SwiftMixTester/SwiftMixTester-Swift.h>: main.m:9:10: error: 'SwiftMixTester/SwiftMixTester-Swift.h' file not found (in target 'CppCallSwift' from project 'CppCallSwift') note: Did not find header 'SwiftMixTester-Swift.h' in framework 'SwiftMixTester' (loaded from '/Users/yanivsmacm4/Library/Developer/Xcode/DerivedData/CppCallSwift-exdxjvwdcczqntbkksebulvfdolq/Build/Products/Debug') . Please help.

I can't find any simple c++ xcodeproj call to swift struct using modern c++ swift mix. there is the fibonacci example that is swift app call to c++. Base on fibonacci example I create new simple project and fail to build it with error when I try to include #include <SwiftMixTester/SwiftMixTester-Swift.h> What is wrong? Is it the right place to ask this? Any work project link? Xcode 26.

Title Why doesn’t this async function see external changes to an inout Bool in Release builds (but works in Debug)? Body I have a small helper function that waits for a Bool flag to become true with a timeout: public func test(binding value: inout Bool, timeout maximum: Int) async throws { var count = 0 while value == false { count += 1 try await Task.sleep(nanoseconds: 0_100_000_000) if value == true { return } if count > (maximum * 10) { return } } } I call like this: var isVPNConnected = false adapter.start(tunnelConfiguration: tunnelConfiguration) { [weak self] adapterError in guard let self = self else { return } if let adapterError = adapterError { } else { isVPNConnected = true } completionHandler(adapterError) } try await waitUntilTrue(binding: &isVPNConnected, timeout: 10) What I expect: test should keep looping until flag becomes true (or the timeout is hit). When the second task sets flag = true, the first task should see that change and return. What actually happens: In Debug builds this behaves as expected: when the second task sets flag = true, the loop inside test eventually exits. In Release builds the function often never sees the change and gets stuck until the timeout (or forever, depending on the code). It looks like the while value == false condition is using some cached value and never observes the external write. So my questions are: Is the compiler allowed to assume that value (the inout Bool) does not change inside the loop, even though there are await suspension points and another task is mutating the same variable? Is this behavior officially “undefined” because I’m sharing a plain Bool across tasks without any synchronization (actors / locks / atomics), so the debug build just happens to work? What is the correct / idiomatic way in Swift concurrency to implement this kind of “wait until flag becomes true with timeout” pattern? Should I avoid inout here completely and use some other primitive (e.g. AsyncStream, CheckedContinuation, Actor, ManagedAtomic, etc.)? Is there any way to force the compiler to re-read the Bool from memory each iteration, or is that the wrong way to think about it? Environment (if it matters): Swift: [fill in your Swift version] Xcode: [fill in your Xcode version] Target: iOS / macOS [fill in as needed] Optimization: default Debug vs. Release settings I’d like to understand why Debug vs Release behaves differently here, and what the recommended design is for this kind of async waiting logic in Swift.

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?

Why doesn’t deinit support async? At the end of a test, I want to wipe data from HealthKit, and it’s delete function is asynchronous.

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.

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!

"the compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions" ...... it killing me !!!!

I recently encountered an issue with Xcode 16.2 while attempting to integrate Settings.bundle into a new app. I added Settings.bundle as a new file (using the provided template), but when I ran the app (the standard simple "Hello World" project), the expected three default controls (Name, Enabled, Slider) did not appear in the app's settings. To troubleshoot, I downgraded my system to macOS Sonoma 14.7.2 and Xcode 15.4 (on a 2023 Mac Mini, M2). After this downgrade, everything worked as expected. With a new project, adding Settings.bundle, and running the app, the settings entry for the app appeared, including the three default fields. This behavior suggests a potential issue or incompatibility with Xcode 16.2.

Hey there- I'm having a quite interesting bug on Swift Playgrounds. I am trying to run my app with this following code snippet which does not compile on Swift Playgrounds, yet compiles on XCode (note: this is a Swift Playground app) if #available(iOS 18.0, *) { //simple function to get the indices of other items that have the same date as the "date" variable let indices = data!.indices(where: { item in let sameMonth = Calendar.current.component(.month, from: item.time) == Calendar.current.component(.month, from: date) let sameYear = Calendar.current.component(.year, from: item.time) == Calendar.current.component(.year, from: date) let sameDay = Calendar.current.component(.day, from: item.time) == Calendar.current.component(.year, from: date) return sameDay && sameMonth && sameYear }) However, the indices(where:) codeblock seems to stop the app from compiling (ONLY on Swift Playgrounds - it works perfectly fine on XCode). I am getting the following error: Cannot call value of non-function type 'Range<Array<Int>.Index>' (aka 'Range<Int>') Please let me know if you have any insight regarding this issue. -ColoredOwl

I’m working with Swift and ran into an issue when using the contains(_:) method on an array. The following code works fine: let result = ["hello", "world"].contains(Optional("hello")) // ✅ Works fine But when I try to use the same contains method with the array declared in a separate variable, I get a compile-time error: let stringArray = ["hello", "world"] let result = stringArray.contains(Optional("hello")) // ❌ Compile-time error Both examples seem conceptually similar, but the second one causes a compile-time error, while the first one works fine. I understand that when comparing an optional value (Optional("hello")) with a non-optional value ("hello"), Swift automatically promotes the non-optional value to an optional (i.e., "hello" becomes Optional("hello")). 🔗 reference What I don’t understand is why the first code works but the second one doesn’t, even though both cases involve comparing an optional value with a non-optional value. I know that there are different ways to resolve this, like using nil coalescing or optional binding, but what I’m really looking for is a detailed explanation of why this issue occurs at the compile-time level. Can anyone explain the underlying reason for this behavior?

I have a macro that converts expression into a string literal, e.g.: #toString(variable) -> "variable" #toString(TypeName) -> "TypeName" #toString(\TypeName.property) -> "property" In Xcode 16.3 #toString(TypeName) stopped to work, compilation throws 'Expected member name or initializer call after type name' error. Everything works fine in Xcode 16.2. I tried to compare build settings between 16.2 and 16.3 but haven't noticed differences that may cause this new error. The following works in both Xcode versions: #toString(variable) -> "variable" #toString(\TypeName.property) -> "property" Seems like Xcode tries to compile code that shouldn't be compiled because of macro expansion. Does anybody know what new has appeared in 16.3 and, perhaps, how to fix the problem?