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Access essential data types, collections, and operating-system services to define the base layer of functionality for your app using Foundation.

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Disable URLSession auto retry policy
We are developing an iOS application that is interacting with HTTP APIs that requires us to put a unique UUID (a nonce) as an header on every request (obviously there's more than that, but that's irrilevant to the question here). If the same nonce is sent on two subsequent requests the server returns a 412 error. We should avoid generating this kind of errors as, if repeated, they may be flagged as a malicious activity by the HTTP APIs. We are using URLSession.shared.dataTaskPublisher(for: request) to call the HTTP APIs with request being generated with the unique nonce as an header. On our field tests we are seeing a few cases of the same HTTP request (same nonce) being repeated a few seconds on after the other. Our code has some retry logic only on 401 errors, but that involves a token refresh, and this is not what we are seeing from logs. We were able to replicate this behaviour on our own device using Network Link Conditioner with very bad performance, with XCode's Network inspector attached we can be certain that two HTTP requests with identical headers are actually made automatically, the first request has an "End Reason" of "Retry", the second is "Success" with Status 412. Our questions are: can we disable this behaviour? can we provide a new request for the retry (so that we can update headers)? Thanks, Francesco
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450
Aug ’25
Crash in WKScriptMessageHandler — CFRelease / CoreFoundation on iOS with WKWebView
We are building a hybrid iOS app using Angular (web) rendered inside a WKWebView, hosted by a native Swift app. Communication between the Angular UI and native Swift code is done using WKScriptMessageHandler. The app mostly works without issues, but in rare edge cases, we’re seeing crashes on the main thread, and the crash is reported in Firebase Crashlytics. The root cause appears related to CFRelease and WKScriptMessageHandler. Here’s the relevant crash stack: Crashed: com.apple.main-thread 0 CoreFoundation 0xbfac CFRelease + 44 1 CoreFoundation 0xa734 __CFURLDeallocate + 128 2 CoreFoundation 0x730c _CFRelease + 292 3 libobjc.A.dylib 0x4e28 AutoreleasePoolPage::releaseUntil(objc_object**) + 204 4 libobjc.A.dylib 0x4cbc objc_autoreleasePoolPop + 260 5 WebKit 0x99f194 WebKit::WebUserContentControllerProxy::didPostMessage(WTF::ObjectIdentifierGeneric<WebKit::WebPageProxyIdentifierType, WTF::ObjectIdentifierMainThreadAccessTraits<unsigned long long>, unsigned long long>, WebKit::FrameInfoData&&, WTF::ObjectIdentifierGeneric<WebKit::ScriptMessageHandlerIdentifierType, WTF::ObjectIdentifierMainThreadAccessTraits<unsigned long long>, unsigned long long>, std::__1::span<unsigned char const, 18446744073709551615ul>, WTF::CompletionHandler<void (std::__1::span<unsigned char const, 18446744073709551615ul>, WTF::String const&)>&&) + 680 6 WebKit 0x1b358 WebKit::WebUserContentControllerProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 392 7 WebKit 0xe86b0 IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) + 272 8 WebKit 0x23c0c WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 44 9 WebKit 0xe3f054 IPC::Connection::dispatchMessage(WTF::UniqueRef<IPC::Decoder>) + 252 10 WebKit 0x332d4 IPC::Connection::dispatchIncomingMessages() + 744 11 JavaScriptCore 0x58a7c WTF::RunLoop::performWork() + 204 12 JavaScriptCore 0x599a4 WTF::RunLoop::performWork(void*) + 36 13 CoreFoundation 0x56328 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 14 CoreFoundation 0x562bc __CFRunLoopDoSource0 + 176 15 CoreFoundation 0x53dc0 __CFRunLoopDoSources0 + 244 16 CoreFoundation 0x52fbc __CFRunLoopRun + 840 17 CoreFoundation 0x52830 CFRunLoopRunSpecific + 588 18 GraphicsServices 0x11c4 GSEventRunModal + 164 19 UIKitCore 0x3d2eb0 -[UIApplication _run] + 816 20 UIKitCore 0x4815b4 UIApplicationMain + 340 21 APP1 0xa2f80 main + 21 (AppDelegate.swift:21) 22 ??? 0x1c234eec8 (シンボルが不足しています) Steps: WebView: WKWebView Message passing: WKScriptMessageHandler → passing data from Angular → Swift WKWebView is long-lived and reused Native is using WKUserContentController.add(_:name:) to register handlers Crashes are intermittent (hard to reproduce), but often follow: Screen sleep/wake Push notification open Angular calling native immediately after resume Questions: Has anyone seen this specific crash pattern involving CFRelease and WKScriptMessageHandler? Are there known WebKit or CoreFoundation bugs related to WKScriptMessageHandler and retained URLs or message content? Thank you for your help!
1
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386
Jul ’25
Weird DateFormatter behavior
I am seeing a weird behavior of the date formatter (Full code is below). When run, this will give the following output: 57: 1 month, 3 weeks, 5 days 58: 1 month, 3 weeks, 6 days 59: 2 months 60: 2 months, 1 day 61: 2 months 62: 2 months, 1 day 63: 2 months, 2 days So both 59 days and 61 days are 2 months, and both 60 and 62 days are 2 months and 1 day. This of course is especially weird because this means, 2 months also comes after 2 months and a day. Can someone explain to me what is going on here? import Foundation let formatter = DateComponentsFormatter() formatter.unitsStyle = .full let calendar = Calendar(identifier: .gregorian) let today = calendar.date(from: DateComponents(year: 2025, month: 7, day: 26))! for day in 57...63 { let startDate = calendar.date(byAdding: .day, value: -day, to: today)! let components = calendar.dateComponents([.day, .weekOfMonth, .month,. year], from: startDate, to: today) let result = formatter.string(from: components)! print ("\(String(format: "%3d", day)): \(result)") }
4
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334
Jul ’25
Accessing security scoped URLs without calling url.startAccessingSecurityScopedResource
I have discovered a gap in my understanding of user selected URLs in iOS, and I would be grateful if someone can put me right please. My understanding is that a URL selected by a user can be accessed by calling url.startAccessingSecurityScopedResource() call. Subsequently a call to stopAccessingSecurityScopedResource() is made to avoid sandbox memory leaks. Furthermore, the URL can be saved as a bookmark and reconstituted when the app is run again to avoid re-asking permission from the user. So far so good. However, I have discovered that a URL retrieved from a bookmark can be accessed without the call to url.startAccessingSecurityScopedResource(). This seems contrary to what the documentation says here So my question is (assuming this is not a bug) why not save and retrieve the URL immediately in order to avoid having to make any additional calls to url.startAccessingSecurityScopedResource? Bill Aylward You can copy and paste the code below into a new iOS project to illustrate this. Having chosen a folder, the 'Summarise folder without permission' button fails as expected, but once the 'Retrieve URL from bookmark' has been pressed, it works fine. import SwiftUI import UniformTypeIdentifiers struct ContentView: View { @AppStorage("bookmarkData") private var bookmarkData: Data? @State private var showFolderPicker = false @State private var folderUrl: URL? @State private var folderReport: String? var body: some View { VStack(spacing: 20) { Text("Selected folder: \(folderUrl?.lastPathComponent ?? "None")") Text("Contents: \(folderReport ?? "Unknown")") Button("Select folder") { showFolderPicker.toggle() } Button("Deselect folder") { folderUrl = nil folderReport = nil bookmarkData = nil } .disabled(folderUrl == nil) Button("Retrieve URL from bookmark") { retrieveFolderURL() } .disabled(bookmarkData == nil) Button("Summarise folder with permission") { summariseFolderWithPermission(true) } .disabled(folderUrl == nil) Button("Summarise folder without permission") { summariseFolderWithPermission(false) } .disabled(folderUrl == nil) } .padding() .fileImporter( isPresented: $showFolderPicker, allowedContentTypes: [UTType.init("public.folder")!], allowsMultipleSelection: false ) { result in switch result { case .success(let urls): if let selectedUrl = urls.first { print("Processing folder: \(selectedUrl)") processFolderURL(selectedUrl) } case .failure(let error): print("\(error.localizedDescription)") } } .onAppear() { guard folderUrl == nil else { return } retrieveFolderURL() } } func processFolderURL(_ selectedUrl: URL?) { guard selectedUrl != nil else { return } // Create and save a security scoped bookmark in AppStorage do { guard selectedUrl!.startAccessingSecurityScopedResource() else { print("Unable to access \(selectedUrl!)"); return } // Save bookmark bookmarkData = try selectedUrl!.bookmarkData(options: .minimalBookmark, includingResourceValuesForKeys: nil, relativeTo: nil) selectedUrl!.stopAccessingSecurityScopedResource() } catch { print("Unable to save security scoped bookmark") } folderUrl = selectedUrl! } func retrieveFolderURL() { guard let bookmarkData = bookmarkData else { print("No bookmark data available") return } do { var isStale = false let url = try URL( resolvingBookmarkData: bookmarkData, options: .withoutUI, relativeTo: nil, bookmarkDataIsStale: &isStale ) folderUrl = url } catch { print("Error accessing URL: \(error.localizedDescription)") } } func summariseFolderWithPermission(_ permission: Bool) { folderReport = nil print(String(describing: folderUrl)) guard folderUrl != nil else { return } if permission { print("Result of access requrest is \(folderUrl!.startAccessingSecurityScopedResource())") } do { let contents = try FileManager.default.contentsOfDirectory(atPath: folderUrl!.path) folderReport = "\(contents.count) files, the first is: \(contents.first!)" } catch { print(error.localizedDescription) } if permission { folderUrl!.stopAccessingSecurityScopedResource() } } }
7
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405
Jul ’25
Share extension with App Group: UserDefaults don't get persisted on iOS
I have a multiplatform app for Mac and iOS, for which I am implementing a share extension. This share extension has to share settings with the app itself on both platforms. I am currently trying to achieve this by adding all targets to the same App Group and using UserDefaults with the App Group as suiteName. The app consists of three targets: A multiplatform SwiftUI app, an iOS Share Extension, and a macOS Share Extension,. Settings get persisted correctly on Mac and on the iOS 26 simulator. However, on a real iOS 26 beta 3 device, the Share Extension is unable to load UserDefaults (loading anything with the App Group as a suite name returns nil). What could cause this behavior? The following log entries are generated from the Share Extension on the iOS device, but not on the iOS simulator: Couldn't read values in CFPrefsPlistSource&lt;0x1030d3c80&gt; (Domain: MY_APP_GROUP, User: kCFPreferencesAnyUser, ByHost: Yes, Container: (null), Contents Need Refresh: Yes): Using kCFPreferencesAnyUser with a container is only allowed for System Containers, detaching from cfprefsd 59638328 Plugin query method called (501) Invalidation handler invoked, clearing connection (501) personaAttributesForPersonaType for type:0 failed with error Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.mobile.usermanagerd.xpc was invalidated from this process." UserInfo={NSDebugDescription=The connection to service named com.apple.mobile.usermanagerd.xpc was invalidated from this process.} LaunchServices: store (null) or url (null) was nil: Error Domain=NSOSStatusErrorDomain Code=-54 "process may not map database" UserInfo={_LSLine=72, _LSFunction=_LSServer_GetServerStoreForConnectionWithCompletionHandler, _LSFile=LSDReadService.mm, NSDebugDescription=process may not map database} Attempt to map database failed: permission was denied. This attempt will not be retried. Failed to initialize client context with error Error Domain=NSOSStatusErrorDomain Code=-54 "process may not map database" UserInfo={_LSLine=72, _LSFunction=_LSServer_GetServerStoreForConnectionWithCompletionHandler, _LSFile=LSDReadService.mm, NSDebugDescription=process may not map database} [C:1-3] Error received: Invalidated by remote connection.
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211
Jul ’25
FileManager.removeItem(atPath:) fails with "You don't have permission to access the file" error when trying to remove non-empty directory on NAS
A user of my app reported that when trying to remove a file it always fails with the error "file couldn't be removed because you don't have permission to access it (Cocoa Error Domain 513)". After some testing, we found out that it's caused by trying to delete non-empty directories. I'm using FileManager.removeItem(atPath:) which has worked fine for many years, but it seems that with their particular NAS, it doesn't work. I could work around this by checking if the file is a directory, and if it is, enumerating the directory and remove each contained file before removing the directory itself. But shouldn't this already be taken care of? In the source code of FileManager I see that for Darwin platforms it calls removefile(pathPtr, state, removefile_flags_t(REMOVEFILE_RECURSIVE)) so it seems that it should already work. Is the REMOVEFILE_RECURSIVE flag perhaps ignored by the device? But then, is the misleading "you don't have permission to access the file" error thrown by the device or by macOS? For the FileManager source code, see https://github.com/swiftlang/swift-foundation/blob/1d5d70997410fc8b7700c8648b10d6fc28194202/Sources/FoundationEssentials/FileManager/FileOperations.swift#L444
8
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297
Jul ’25
FileManager.copyItem(atPath:toPath:) not working since iOS / iPad OS 18.4
Hi there, I have discovered that the behavior of file copying has changed starting from iOS 18.4. When using FileManager.copyItem(atPath:toPath:) to copy a directory specified as an argument, whether or not there is a trailing slash ('/') affects whether the copy process works correctly. The same process operates as expected in the iOS 18.3.1 Simulator. Is this the correct behavior, or could it be a bug? The application's build environment is Xcode 16.2. Below is an example of the code. In practice, the file copying is performed within the application's folder. // Both iOS 18.3.1 and iOS 18.4 successfully complete the copy process. FileManager.default.copyItem(atPath: "/path/from/dirA", toPath: "/path/to/dirB") FileManager.default.copyItem(atPath: "/path/from/dirA/", toPath: "/path/to/dirB/") // iOS 18.3.1 successfully complete the copy process, but iOS 18.4 fails. FileManager.default.copyItem(atPath: "/path/from/dirA/", toPath: "/path/to/dirB") I hope this helps Apple engineers and other developers experiencing the same issue. Feedback or additional insights would be appreciated.
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176
Jul ’25
Swapping the `objectAtIndex:` method of `__NSArrayM` using `method_exchangeImplementations` will lead to continuous memory growth.
After swapping the -objectAtIndex: method using method_exchangeImplementations, it will cause continuous memory growth. Connect the iPhone and run the provided project. Continuously tap the iPhone screen. Observe Memory; it will keep growing. Sample code
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982
Jul ’25
FileManager.contentsEqual(atPath:andPath:) very slow
Until now I was using FileManager.contentsEqual(atPath:andPath:) to compare file contents in my App Store app, but then a user reported that this operation is way slower than just copying the files (which I made faster a while ago, as explained in Making filecopy faster by changing block size). I thought that maybe the FileManager implementation reads the two files with a small block size, so I implemented a custom comparison with the same block size I use for filecopy (as explained in the linked post), and it runs much faster. When using the code for testing repeatedly also found on that other post, this new implementation is about the same speed as FileManager for 1KB files, but runs 10-20x faster for 1MB files or bigger. Feel free to comment on my implementation below. extension FileManager { func fastContentsEqual(atPath path1: String, andPath path2: String, progress: (_ delta: Int) -> Bool) -> Bool { do { let bufferSize = 16_777_216 let sourceDescriptor = open(path1, O_RDONLY | O_NOFOLLOW, 0) if sourceDescriptor < 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } let sourceFile = FileHandle(fileDescriptor: sourceDescriptor) let destinationDescriptor = open(path2, O_RDONLY | O_NOFOLLOW, 0) if destinationDescriptor < 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } let destinationFile = FileHandle(fileDescriptor: destinationDescriptor) var equal = true while autoreleasepool(invoking: { let sourceData = sourceFile.readData(ofLength: bufferSize) let destinationData = destinationFile.readData(ofLength: bufferSize) equal = sourceData == destinationData return sourceData.count > 0 && progress(sourceData.count) && equal }) { } if close(sourceDescriptor) < 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } if close(destinationDescriptor) < 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } return equal } catch { return contentsEqual(atPath: path1, andPath: path2) // use this as a fallback for unsupported files (like symbolic links) } } }
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241
Jul ’25
Keyboard becomes unresponsive after backgrounding app while iCloud Keychain “Save Password?” sheet is visible
Product & Version: iOS 17.5.1 (21F90) – reproducible since iOS 13 Test devices: iPhone 14 Pro, iPhone 15, iPad (10th gen) Category: UIKit → Text Input / Keyboard Summary: If the system “Save Password?” prompt (shown by iCloud Keychain after a successful login) is onscreen and the user sends the app to background (Home gesture / App Switcher), the prompt is automatically dismissed. When the app returns to foreground, the keyboard does not appear, and text input is impossible in the entire app until it is force-quit. Steps to Reproduce: Run any app from AppStore that shows "Save Password" alert. Enter any credentials and tap Login, iOS shows the system “Save Password?” alert. Without interacting with the alert, swipe up to the Home screen (or open the App Switcher). Reactivate the app. Tap the text field in the app.
2
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109
Jul ’25
Memory Zeroing Issue After iOS 18 Update
After iOS 18, some new categories of crash exceptions appeared online, such as those related to the sqlite pcache1 module, those related to the photo album PHAsset, those related to various objc_release crashes, etc. These crash scenarios and stacks are all different, but they all share a common feature, that is, they all crash due to accessing NULL or NULL addresses with a certain offset. According to the analysis, the direct cause is that a certain pointer, which previously pointed to valid memory content, has now become pointing to 0 incorrectly and mysteriously. We tried various methods to eliminate issues such as multi-threading problems. To determine the cause of the problem, we have a simulated malloc guard detection in production. The principle is very simple: Create some private NSString objects with random lengths, but ensure that they exceed the size of one memory physical page. Set the first page of memory for these objects to read-only (aligning the object address with the memory page). After a random period of time (3s - 10s), reset the memory of these objects to read/write and immediately release these objects. Then repeat the operation starting from step 1. In this way, if an abnormal write operation is performed on the memory of these objects, it will trigger a read-only exception crash and report the exception stack. Surprisingly, after the malloc guard detection was implemented, some crashes occurred online. However, the crashes were not caused by any abnormal rewriting of read-only memory. Instead, they occurred when the NSString objects were released as mentioned earlier, and the pointers pointed to contents of 0. Therefore, we have added object memory content printing after object generation, before and after setting to read-only, and before and after reverting to read-write. The result was once again unexpected. The log showed that the isa pointer of the object became 0 after setting to read-only and before re-setting to read-write. So why did it become 0 during read-only mode, but no crash occurred due to the read-only status? We have revised the plan again. We have added a test group, in which after the object is created, we will mlock the memory of the object, and then munlock it again before the object is released. As a result, the test analysis showed that the test group did not experience a crash, while the crashes occurred entirely in the control group. In this way, we can prove that the problem occurs at the system level and is related to the virtual memory function of the operating system. It is possible that inactive memory pages are compressed and then cleared to zero, and subsequent decompression fails. This results in the accidental zeroing out of the memory data. As mentioned at the beginning, althougth this issue is a very rare occurrence, but it exists in various scenarios. definitely It appeared after iOS 18. We hope that the authorities will pay attention to this issue and fix it in future versions.
4
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271
Jul ’25
Access resource in swift package from xcframework
I have an iOS app that includes a local Swift package. This Swift package contains some .plist files added as resources. The package also depends on an XCFramework. I want to read these .plist files from within the XCFramework. What I’d like to know is: Is this a common or recommended approach—having resources in a Swift package and accessing them from an XCFramework? Previously, I had the .plist files added directly to the main app target, and accessing them from the XCFramework felt straightforward. With the new setup, I’m trying to determine whether this method (placing resources in a Swift package and accessing them from an XCFramework) is considered good practice. For context: I am currently able to read the .plist files from the XCFramework by passing Bundle.module through one of the APIs exposed by the XCFramework.
3
1
221
Jun ’25
NSuserdefault issue after restart my iphone
hi,guys.There's a issue about my app about NSuserdefault. Everything is arlright if i stay in the app, once i close my app, and restart it.Datas from nsuserdefault is gone(nil). i tried to add and delete synchronize method , but its not working. But this situation only happens in ios 18.(at least ios12 and ios16 is alright).
3
0
193
Jun ’25
Crash with NSAttributedString in Core Data
I am trying out the new AttributedString binding with SwiftUI’s TextEditor in iOS26. I need to save this to a Core Data database. Core Data has no AttributedString type, so I set the type of the field to “Transformable”, give it a custom class of NSAttributedString, and set the transformer to NSSecureUnarchiveFromData When I try to save, I first convert the Swift AttributedString to NSAttributedString, and then save the context. Unfortunately I get this error when saving the context, and the save isn't persisted: CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x600003721140> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null) Here's the code that tries to save the attributed string: struct AttributedDetailView: View { @ObservedObject var item: Item @State private var notesText = AttributedString() var body: some View { VStack { TextEditor(text: $notesText) .padding() .onChange(of: notesText) { item.attributedString = NSAttributedString(notesText) } } .onAppear { if let nsattributed = item.attributedString { notesText = AttributedString(nsattributed) } else { notesText = "" } } .task { item.attributedString = NSAttributedString(notesText) do { try item.managedObjectContext?.save() } catch { print("core data save error = \(error)") } } } } This is the attribute setup in the Core Data model editor: Is there a workaround for this? I filed FB17943846 if someone can take a look. Thanks.
2
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272
Jun ’25
Disable URLSession auto retry policy
We are developing an iOS application that is interacting with HTTP APIs that requires us to put a unique UUID (a nonce) as an header on every request (obviously there's more than that, but that's irrilevant to the question here). If the same nonce is sent on two subsequent requests the server returns a 412 error. We should avoid generating this kind of errors as, if repeated, they may be flagged as a malicious activity by the HTTP APIs. We are using URLSession.shared.dataTaskPublisher(for: request) to call the HTTP APIs with request being generated with the unique nonce as an header. On our field tests we are seeing a few cases of the same HTTP request (same nonce) being repeated a few seconds on after the other. Our code has some retry logic only on 401 errors, but that involves a token refresh, and this is not what we are seeing from logs. We were able to replicate this behaviour on our own device using Network Link Conditioner with very bad performance, with XCode's Network inspector attached we can be certain that two HTTP requests with identical headers are actually made automatically, the first request has an "End Reason" of "Retry", the second is "Success" with Status 412. Our questions are: can we disable this behaviour? can we provide a new request for the retry (so that we can update headers)? Thanks, Francesco
Replies
7
Boosts
3
Views
450
Activity
Aug ’25
'init(contentsOfFile:)' was deprecated in iOS 18
content = try String(contentsOfFile: filepath) is the following warning. 'init(contentsOfFile:)' was deprecated in iOS 18: Use init(contentsOfFile:encoding:) instead After internet searching I could find an answer. I would appreciate a rewrite of my code line to get rid of 31 warnings. Thanks a LOT Charlie
Replies
6
Boosts
0
Views
333
Activity
Jul ’25
Crash in WKScriptMessageHandler — CFRelease / CoreFoundation on iOS with WKWebView
We are building a hybrid iOS app using Angular (web) rendered inside a WKWebView, hosted by a native Swift app. Communication between the Angular UI and native Swift code is done using WKScriptMessageHandler. The app mostly works without issues, but in rare edge cases, we’re seeing crashes on the main thread, and the crash is reported in Firebase Crashlytics. The root cause appears related to CFRelease and WKScriptMessageHandler. Here’s the relevant crash stack: Crashed: com.apple.main-thread 0 CoreFoundation 0xbfac CFRelease + 44 1 CoreFoundation 0xa734 __CFURLDeallocate + 128 2 CoreFoundation 0x730c _CFRelease + 292 3 libobjc.A.dylib 0x4e28 AutoreleasePoolPage::releaseUntil(objc_object**) + 204 4 libobjc.A.dylib 0x4cbc objc_autoreleasePoolPop + 260 5 WebKit 0x99f194 WebKit::WebUserContentControllerProxy::didPostMessage(WTF::ObjectIdentifierGeneric<WebKit::WebPageProxyIdentifierType, WTF::ObjectIdentifierMainThreadAccessTraits<unsigned long long>, unsigned long long>, WebKit::FrameInfoData&&, WTF::ObjectIdentifierGeneric<WebKit::ScriptMessageHandlerIdentifierType, WTF::ObjectIdentifierMainThreadAccessTraits<unsigned long long>, unsigned long long>, std::__1::span<unsigned char const, 18446744073709551615ul>, WTF::CompletionHandler<void (std::__1::span<unsigned char const, 18446744073709551615ul>, WTF::String const&)>&&) + 680 6 WebKit 0x1b358 WebKit::WebUserContentControllerProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 392 7 WebKit 0xe86b0 IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) + 272 8 WebKit 0x23c0c WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 44 9 WebKit 0xe3f054 IPC::Connection::dispatchMessage(WTF::UniqueRef<IPC::Decoder>) + 252 10 WebKit 0x332d4 IPC::Connection::dispatchIncomingMessages() + 744 11 JavaScriptCore 0x58a7c WTF::RunLoop::performWork() + 204 12 JavaScriptCore 0x599a4 WTF::RunLoop::performWork(void*) + 36 13 CoreFoundation 0x56328 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 14 CoreFoundation 0x562bc __CFRunLoopDoSource0 + 176 15 CoreFoundation 0x53dc0 __CFRunLoopDoSources0 + 244 16 CoreFoundation 0x52fbc __CFRunLoopRun + 840 17 CoreFoundation 0x52830 CFRunLoopRunSpecific + 588 18 GraphicsServices 0x11c4 GSEventRunModal + 164 19 UIKitCore 0x3d2eb0 -[UIApplication _run] + 816 20 UIKitCore 0x4815b4 UIApplicationMain + 340 21 APP1 0xa2f80 main + 21 (AppDelegate.swift:21) 22 ??? 0x1c234eec8 (シンボルが不足しています) Steps: WebView: WKWebView Message passing: WKScriptMessageHandler → passing data from Angular → Swift WKWebView is long-lived and reused Native is using WKUserContentController.add(_:name:) to register handlers Crashes are intermittent (hard to reproduce), but often follow: Screen sleep/wake Push notification open Angular calling native immediately after resume Questions: Has anyone seen this specific crash pattern involving CFRelease and WKScriptMessageHandler? Are there known WebKit or CoreFoundation bugs related to WKScriptMessageHandler and retained URLs or message content? Thank you for your help!
Replies
1
Boosts
0
Views
386
Activity
Jul ’25
Weird DateFormatter behavior
I am seeing a weird behavior of the date formatter (Full code is below). When run, this will give the following output: 57: 1 month, 3 weeks, 5 days 58: 1 month, 3 weeks, 6 days 59: 2 months 60: 2 months, 1 day 61: 2 months 62: 2 months, 1 day 63: 2 months, 2 days So both 59 days and 61 days are 2 months, and both 60 and 62 days are 2 months and 1 day. This of course is especially weird because this means, 2 months also comes after 2 months and a day. Can someone explain to me what is going on here? import Foundation let formatter = DateComponentsFormatter() formatter.unitsStyle = .full let calendar = Calendar(identifier: .gregorian) let today = calendar.date(from: DateComponents(year: 2025, month: 7, day: 26))! for day in 57...63 { let startDate = calendar.date(byAdding: .day, value: -day, to: today)! let components = calendar.dateComponents([.day, .weekOfMonth, .month,. year], from: startDate, to: today) let result = formatter.string(from: components)! print ("\(String(format: "%3d", day)): \(result)") }
Replies
4
Boosts
0
Views
334
Activity
Jul ’25
Failed to obtain timestamp in 12-hour format
When the iPhone is set to 12-hour time format, obtaining a timestamp similar to "2025-07-18 16:29:00" fails
Replies
2
Boosts
0
Views
209
Activity
Jul ’25
Accessing security scoped URLs without calling url.startAccessingSecurityScopedResource
I have discovered a gap in my understanding of user selected URLs in iOS, and I would be grateful if someone can put me right please. My understanding is that a URL selected by a user can be accessed by calling url.startAccessingSecurityScopedResource() call. Subsequently a call to stopAccessingSecurityScopedResource() is made to avoid sandbox memory leaks. Furthermore, the URL can be saved as a bookmark and reconstituted when the app is run again to avoid re-asking permission from the user. So far so good. However, I have discovered that a URL retrieved from a bookmark can be accessed without the call to url.startAccessingSecurityScopedResource(). This seems contrary to what the documentation says here So my question is (assuming this is not a bug) why not save and retrieve the URL immediately in order to avoid having to make any additional calls to url.startAccessingSecurityScopedResource? Bill Aylward You can copy and paste the code below into a new iOS project to illustrate this. Having chosen a folder, the 'Summarise folder without permission' button fails as expected, but once the 'Retrieve URL from bookmark' has been pressed, it works fine. import SwiftUI import UniformTypeIdentifiers struct ContentView: View { @AppStorage("bookmarkData") private var bookmarkData: Data? @State private var showFolderPicker = false @State private var folderUrl: URL? @State private var folderReport: String? var body: some View { VStack(spacing: 20) { Text("Selected folder: \(folderUrl?.lastPathComponent ?? "None")") Text("Contents: \(folderReport ?? "Unknown")") Button("Select folder") { showFolderPicker.toggle() } Button("Deselect folder") { folderUrl = nil folderReport = nil bookmarkData = nil } .disabled(folderUrl == nil) Button("Retrieve URL from bookmark") { retrieveFolderURL() } .disabled(bookmarkData == nil) Button("Summarise folder with permission") { summariseFolderWithPermission(true) } .disabled(folderUrl == nil) Button("Summarise folder without permission") { summariseFolderWithPermission(false) } .disabled(folderUrl == nil) } .padding() .fileImporter( isPresented: $showFolderPicker, allowedContentTypes: [UTType.init("public.folder")!], allowsMultipleSelection: false ) { result in switch result { case .success(let urls): if let selectedUrl = urls.first { print("Processing folder: \(selectedUrl)") processFolderURL(selectedUrl) } case .failure(let error): print("\(error.localizedDescription)") } } .onAppear() { guard folderUrl == nil else { return } retrieveFolderURL() } } func processFolderURL(_ selectedUrl: URL?) { guard selectedUrl != nil else { return } // Create and save a security scoped bookmark in AppStorage do { guard selectedUrl!.startAccessingSecurityScopedResource() else { print("Unable to access \(selectedUrl!)"); return } // Save bookmark bookmarkData = try selectedUrl!.bookmarkData(options: .minimalBookmark, includingResourceValuesForKeys: nil, relativeTo: nil) selectedUrl!.stopAccessingSecurityScopedResource() } catch { print("Unable to save security scoped bookmark") } folderUrl = selectedUrl! } func retrieveFolderURL() { guard let bookmarkData = bookmarkData else { print("No bookmark data available") return } do { var isStale = false let url = try URL( resolvingBookmarkData: bookmarkData, options: .withoutUI, relativeTo: nil, bookmarkDataIsStale: &isStale ) folderUrl = url } catch { print("Error accessing URL: \(error.localizedDescription)") } } func summariseFolderWithPermission(_ permission: Bool) { folderReport = nil print(String(describing: folderUrl)) guard folderUrl != nil else { return } if permission { print("Result of access requrest is \(folderUrl!.startAccessingSecurityScopedResource())") } do { let contents = try FileManager.default.contentsOfDirectory(atPath: folderUrl!.path) folderReport = "\(contents.count) files, the first is: \(contents.first!)" } catch { print(error.localizedDescription) } if permission { folderUrl!.stopAccessingSecurityScopedResource() } } }
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405
Activity
Jul ’25
Share extension with App Group: UserDefaults don't get persisted on iOS
I have a multiplatform app for Mac and iOS, for which I am implementing a share extension. This share extension has to share settings with the app itself on both platforms. I am currently trying to achieve this by adding all targets to the same App Group and using UserDefaults with the App Group as suiteName. The app consists of three targets: A multiplatform SwiftUI app, an iOS Share Extension, and a macOS Share Extension,. Settings get persisted correctly on Mac and on the iOS 26 simulator. However, on a real iOS 26 beta 3 device, the Share Extension is unable to load UserDefaults (loading anything with the App Group as a suite name returns nil). What could cause this behavior? The following log entries are generated from the Share Extension on the iOS device, but not on the iOS simulator: Couldn't read values in CFPrefsPlistSource&lt;0x1030d3c80&gt; (Domain: MY_APP_GROUP, User: kCFPreferencesAnyUser, ByHost: Yes, Container: (null), Contents Need Refresh: Yes): Using kCFPreferencesAnyUser with a container is only allowed for System Containers, detaching from cfprefsd 59638328 Plugin query method called (501) Invalidation handler invoked, clearing connection (501) personaAttributesForPersonaType for type:0 failed with error Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.mobile.usermanagerd.xpc was invalidated from this process." UserInfo={NSDebugDescription=The connection to service named com.apple.mobile.usermanagerd.xpc was invalidated from this process.} LaunchServices: store (null) or url (null) was nil: Error Domain=NSOSStatusErrorDomain Code=-54 "process may not map database" UserInfo={_LSLine=72, _LSFunction=_LSServer_GetServerStoreForConnectionWithCompletionHandler, _LSFile=LSDReadService.mm, NSDebugDescription=process may not map database} Attempt to map database failed: permission was denied. This attempt will not be retried. Failed to initialize client context with error Error Domain=NSOSStatusErrorDomain Code=-54 "process may not map database" UserInfo={_LSLine=72, _LSFunction=_LSServer_GetServerStoreForConnectionWithCompletionHandler, _LSFile=LSDReadService.mm, NSDebugDescription=process may not map database} [C:1-3] Error received: Invalidated by remote connection.
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1
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211
Activity
Jul ’25
FileManager.removeItem(atPath:) fails with "You don't have permission to access the file" error when trying to remove non-empty directory on NAS
A user of my app reported that when trying to remove a file it always fails with the error "file couldn't be removed because you don't have permission to access it (Cocoa Error Domain 513)". After some testing, we found out that it's caused by trying to delete non-empty directories. I'm using FileManager.removeItem(atPath:) which has worked fine for many years, but it seems that with their particular NAS, it doesn't work. I could work around this by checking if the file is a directory, and if it is, enumerating the directory and remove each contained file before removing the directory itself. But shouldn't this already be taken care of? In the source code of FileManager I see that for Darwin platforms it calls removefile(pathPtr, state, removefile_flags_t(REMOVEFILE_RECURSIVE)) so it seems that it should already work. Is the REMOVEFILE_RECURSIVE flag perhaps ignored by the device? But then, is the misleading "you don't have permission to access the file" error thrown by the device or by macOS? For the FileManager source code, see https://github.com/swiftlang/swift-foundation/blob/1d5d70997410fc8b7700c8648b10d6fc28194202/Sources/FoundationEssentials/FileManager/FileOperations.swift#L444
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8
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297
Activity
Jul ’25
FileManager.copyItem(atPath:toPath:) not working since iOS / iPad OS 18.4
Hi there, I have discovered that the behavior of file copying has changed starting from iOS 18.4. When using FileManager.copyItem(atPath:toPath:) to copy a directory specified as an argument, whether or not there is a trailing slash ('/') affects whether the copy process works correctly. The same process operates as expected in the iOS 18.3.1 Simulator. Is this the correct behavior, or could it be a bug? The application's build environment is Xcode 16.2. Below is an example of the code. In practice, the file copying is performed within the application's folder. // Both iOS 18.3.1 and iOS 18.4 successfully complete the copy process. FileManager.default.copyItem(atPath: "/path/from/dirA", toPath: "/path/to/dirB") FileManager.default.copyItem(atPath: "/path/from/dirA/", toPath: "/path/to/dirB/") // iOS 18.3.1 successfully complete the copy process, but iOS 18.4 fails. FileManager.default.copyItem(atPath: "/path/from/dirA/", toPath: "/path/to/dirB") I hope this helps Apple engineers and other developers experiencing the same issue. Feedback or additional insights would be appreciated.
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176
Activity
Jul ’25
Creating hard links on SMB volume
When I connect to another Mac via Finder (using SMB), creating a hard link with FileManager.linkItem(atPath:toPath:) fails (both source and destination are on the remote Mac). I read online that SMB itself supports creating hard links, so is this a macOS limitation or bug?
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2
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152
Activity
Jul ’25
AppleTV Timezone Values Mismatch
App includes a functionality based on each Timezone. As i have fetched some of the Timezone values got some mismatched values compared to actual. e.g: America/Denver values is -6 but got -5 Need support regarding fixing this issue.
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3
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444
Activity
Jul ’25
Swapping the `objectAtIndex:` method of `__NSArrayM` using `method_exchangeImplementations` will lead to continuous memory growth.
After swapping the -objectAtIndex: method using method_exchangeImplementations, it will cause continuous memory growth. Connect the iPhone and run the provided project. Continuously tap the iPhone screen. Observe Memory; it will keep growing. Sample code
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2
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982
Activity
Jul ’25
FileManager.contentsEqual(atPath:andPath:) very slow
Until now I was using FileManager.contentsEqual(atPath:andPath:) to compare file contents in my App Store app, but then a user reported that this operation is way slower than just copying the files (which I made faster a while ago, as explained in Making filecopy faster by changing block size). I thought that maybe the FileManager implementation reads the two files with a small block size, so I implemented a custom comparison with the same block size I use for filecopy (as explained in the linked post), and it runs much faster. When using the code for testing repeatedly also found on that other post, this new implementation is about the same speed as FileManager for 1KB files, but runs 10-20x faster for 1MB files or bigger. Feel free to comment on my implementation below. extension FileManager { func fastContentsEqual(atPath path1: String, andPath path2: String, progress: (_ delta: Int) -> Bool) -> Bool { do { let bufferSize = 16_777_216 let sourceDescriptor = open(path1, O_RDONLY | O_NOFOLLOW, 0) if sourceDescriptor < 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } let sourceFile = FileHandle(fileDescriptor: sourceDescriptor) let destinationDescriptor = open(path2, O_RDONLY | O_NOFOLLOW, 0) if destinationDescriptor < 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } let destinationFile = FileHandle(fileDescriptor: destinationDescriptor) var equal = true while autoreleasepool(invoking: { let sourceData = sourceFile.readData(ofLength: bufferSize) let destinationData = destinationFile.readData(ofLength: bufferSize) equal = sourceData == destinationData return sourceData.count > 0 && progress(sourceData.count) && equal }) { } if close(sourceDescriptor) < 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } if close(destinationDescriptor) < 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } return equal } catch { return contentsEqual(atPath: path1, andPath: path2) // use this as a fallback for unsupported files (like symbolic links) } } }
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241
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Jul ’25
User Data In-App Deletion for Government Apps
Hey, there are plans to design a government app. When a citizen will login they will see their passport, driving license etc... What is the solution of avoiding mandatory in-app user data deletion?
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591
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Jul ’25
Keyboard becomes unresponsive after backgrounding app while iCloud Keychain “Save Password?” sheet is visible
Product & Version: iOS 17.5.1 (21F90) – reproducible since iOS 13 Test devices: iPhone 14 Pro, iPhone 15, iPad (10th gen) Category: UIKit → Text Input / Keyboard Summary: If the system “Save Password?” prompt (shown by iCloud Keychain after a successful login) is onscreen and the user sends the app to background (Home gesture / App Switcher), the prompt is automatically dismissed. When the app returns to foreground, the keyboard does not appear, and text input is impossible in the entire app until it is force-quit. Steps to Reproduce: Run any app from AppStore that shows "Save Password" alert. Enter any credentials and tap Login, iOS shows the system “Save Password?” alert. Without interacting with the alert, swipe up to the Home screen (or open the App Switcher). Reactivate the app. Tap the text field in the app.
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109
Activity
Jul ’25
[[UIDevice currentDevice] systemVersion] issue in iOS 26
We are testing our existing live build, which was prepared with Xcode 16.2, on iOS 26 beta for experience assurance and found that the [[UIDevice currentDevice] systemVersion] API is returning iOS 19 instead of the expected version iOS 26. Has anyone else observed this issue?
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639
Activity
Jul ’25
Memory Zeroing Issue After iOS 18 Update
After iOS 18, some new categories of crash exceptions appeared online, such as those related to the sqlite pcache1 module, those related to the photo album PHAsset, those related to various objc_release crashes, etc. These crash scenarios and stacks are all different, but they all share a common feature, that is, they all crash due to accessing NULL or NULL addresses with a certain offset. According to the analysis, the direct cause is that a certain pointer, which previously pointed to valid memory content, has now become pointing to 0 incorrectly and mysteriously. We tried various methods to eliminate issues such as multi-threading problems. To determine the cause of the problem, we have a simulated malloc guard detection in production. The principle is very simple: Create some private NSString objects with random lengths, but ensure that they exceed the size of one memory physical page. Set the first page of memory for these objects to read-only (aligning the object address with the memory page). After a random period of time (3s - 10s), reset the memory of these objects to read/write and immediately release these objects. Then repeat the operation starting from step 1. In this way, if an abnormal write operation is performed on the memory of these objects, it will trigger a read-only exception crash and report the exception stack. Surprisingly, after the malloc guard detection was implemented, some crashes occurred online. However, the crashes were not caused by any abnormal rewriting of read-only memory. Instead, they occurred when the NSString objects were released as mentioned earlier, and the pointers pointed to contents of 0. Therefore, we have added object memory content printing after object generation, before and after setting to read-only, and before and after reverting to read-write. The result was once again unexpected. The log showed that the isa pointer of the object became 0 after setting to read-only and before re-setting to read-write. So why did it become 0 during read-only mode, but no crash occurred due to the read-only status? We have revised the plan again. We have added a test group, in which after the object is created, we will mlock the memory of the object, and then munlock it again before the object is released. As a result, the test analysis showed that the test group did not experience a crash, while the crashes occurred entirely in the control group. In this way, we can prove that the problem occurs at the system level and is related to the virtual memory function of the operating system. It is possible that inactive memory pages are compressed and then cleared to zero, and subsequent decompression fails. This results in the accidental zeroing out of the memory data. As mentioned at the beginning, althougth this issue is a very rare occurrence, but it exists in various scenarios. definitely It appeared after iOS 18. We hope that the authorities will pay attention to this issue and fix it in future versions.
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4
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271
Activity
Jul ’25
Access resource in swift package from xcframework
I have an iOS app that includes a local Swift package. This Swift package contains some .plist files added as resources. The package also depends on an XCFramework. I want to read these .plist files from within the XCFramework. What I’d like to know is: Is this a common or recommended approach—having resources in a Swift package and accessing them from an XCFramework? Previously, I had the .plist files added directly to the main app target, and accessing them from the XCFramework felt straightforward. With the new setup, I’m trying to determine whether this method (placing resources in a Swift package and accessing them from an XCFramework) is considered good practice. For context: I am currently able to read the .plist files from the XCFramework by passing Bundle.module through one of the APIs exposed by the XCFramework.
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221
Activity
Jun ’25
NSuserdefault issue after restart my iphone
hi,guys.There's a issue about my app about NSuserdefault. Everything is arlright if i stay in the app, once i close my app, and restart it.Datas from nsuserdefault is gone(nil). i tried to add and delete synchronize method , but its not working. But this situation only happens in ios 18.(at least ios12 and ios16 is alright).
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193
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Jun ’25
Crash with NSAttributedString in Core Data
I am trying out the new AttributedString binding with SwiftUI’s TextEditor in iOS26. I need to save this to a Core Data database. Core Data has no AttributedString type, so I set the type of the field to “Transformable”, give it a custom class of NSAttributedString, and set the transformer to NSSecureUnarchiveFromData When I try to save, I first convert the Swift AttributedString to NSAttributedString, and then save the context. Unfortunately I get this error when saving the context, and the save isn't persisted: CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x600003721140> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null) Here's the code that tries to save the attributed string: struct AttributedDetailView: View { @ObservedObject var item: Item @State private var notesText = AttributedString() var body: some View { VStack { TextEditor(text: $notesText) .padding() .onChange(of: notesText) { item.attributedString = NSAttributedString(notesText) } } .onAppear { if let nsattributed = item.attributedString { notesText = AttributedString(nsattributed) } else { notesText = "" } } .task { item.attributedString = NSAttributedString(notesText) do { try item.managedObjectContext?.save() } catch { print("core data save error = \(error)") } } } } This is the attribute setup in the Core Data model editor: Is there a workaround for this? I filed FB17943846 if someone can take a look. Thanks.
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272
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Jun ’25