Issue: Background downloads using the flutter_downloader package work perfectly in debug mode and release mode when run directly from Xcode (plugged in). However, when I create an archive build and install the app separately (via TestFlight or direct IPA install), the background download stops working as soon as the app is minimized. ✅ What I’ve already done Info.plist <key>UIBackgroundModes</key> <array> <string>remote-notification</string> <string>fetch</string> <string>processing</string> <string>audio</string> <string>push-to-talk</string> </array> AppDelegate.swift import UIKit import Flutter import Firebase import flutter_downloader import BackgroundTasks @main @objc class AppDelegate: FlutterAppDelegate { static let backgroundChannel = "com.example.app/background_service" private var backgroundCompletionHandler: (() -> Void)? override func application( _ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? ) -> Bool { FirebaseApp.configure() GeneratedPluginRegistrant.register(with: self) FlutterDownloaderPlugin.setPluginRegistrantCallback(registerPlugins) if #available(iOS 10.0, *) { UNUserNotificationCenter.current().delegate = self } if #available(iOS 13.0, *) { registerBackgroundTask() } return super.application(application, didFinishLaunchingWithOptions: launchOptions) } @available(iOS 13.0, *) private func registerBackgroundTask() { BGTaskScheduler.shared.register( forTaskWithIdentifier: "com.example.app.process_download_queue", using: nil ) { [weak self] task in guard let self = self else { return } self.handleDownloadQueueTask(task: task as! BGProcessingTask) } } @available(iOS 13.0, *) private func handleDownloadQueueTask(task: BGProcessingTask) { scheduleNextDownloadTask() let headlessEngine = FlutterEngine(name: "BackgroundTaskEngine", project: nil, allowHeadlessExecution: true) headlessEngine.run() let channel = FlutterMethodChannel( name: AppDelegate.backgroundChannel, binaryMessenger: headlessEngine.binaryMessenger ) task.expirationHandler = { channel.invokeMethod("backgroundTaskExpired", arguments: nil) } channel.invokeMethod("processNextInBackground", arguments: nil) { result in task.setTaskCompleted(success: (result as? Bool) ?? false) } } override func application( _ application: UIApplication, handleEventsForBackgroundURLSession identifier: String, completionHandler: @escaping () -> Void ) { self.backgroundCompletionHandler = completionHandler super.application(application, handleEventsForBackgroundURLSession: identifier, completionHandler: completionHandler) } override func applicationDidEnterBackground(_ application: UIApplication) { if #available(iOS 13.0, *) { scheduleNextDownloadTask() } } @available(iOS 10.0, *) override func userNotificationCenter( _ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void ) { if #available(iOS 14.0, *) { completionHandler([.list, .banner, .badge, .sound]) } else { completionHandler([.alert, .badge, .sound]) } } @available(iOS 10.0, *) override func userNotificationCenter( _ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void ) { completionHandler() } } // MARK: - Helper @available(iOS 13.0, *) func scheduleNextDownloadTask() { let request = BGProcessingTaskRequest(identifier: "com.example.app.process_download_queue") request.requiresNetworkConnectivity = true request.requiresExternalPower = false request.earliestBeginDate = Date(timeIntervalSinceNow: 60) do { try BGTaskScheduler.shared.submit(request) print("BGTask: Download queue processing task scheduled successfully.") } catch { print("BGTask: Could not schedule download queue task: \(error)") } } private func registerPlugins(registry: FlutterPluginRegistry) { if !registry.hasPlugin("FlutterDownloaderPlugin") { FlutterDownloaderPlugin.register(with: registry.registrar(forPlugin: "FlutterDownloaderPlugin")!) } } 🧩 Observations Background download works correctly when: The app is plugged in and run via Xcode (release/debug) It stops working when: The app is installed from an archived build (IPA/TestFlight) and minimized All entitlements and background modes are properly added. Provisioning profile includes required background modes. ❓Question Is there any known limitation or signing difference between Xcode run and archived release builds that could cause URLSession background tasks not to trigger? Has anyone faced a similar issue when using flutter_downloader on iOS 13+ with BGTaskScheduler or URLSession background configuration? Any help or working setup example for production/TestFlight would be appreciated.

Say I want to sync a toggle in my app with SMAppService's .status property. If the status changes from my app I can track it. But if user toggles it from System Settings, I don't see a notification so then the UI in my app is out of date. The status property is not key value observable and there doesn't appear to be a SMAppServiceStatusDidChangeNotification ? I can re-read it every time my app will become active but feels kind of wrong to do it this way.

I am using C APIs for XPC communication. When my XPC server gets a xpc_dictionary as a message, I use xpc_dictionary_get_string to get the string which is of type const char*. Afterwards, when I try to free up the memory for the string, I get an error. I could not find any details on why this happens. Does XPC handle the lifecycle of these C strings ? I did some tests to see the behaviour. The following code snippet prints a string temp before and after releasing the dictionary memory. char* string = "dummy-string"; xpc_object_t dict = xpc_dictionary_create(NULL, NULL, 0); xpc_dictionary_set_string(dict, "str", string); const char* temp = xpc_dictionary_get_string(reply, "str"); printf("temp before release: %s\n", temp); xpc_release(reply); printf("temp after release: %s\n", temp); output: # temp before release: dummy-string # temp after release: I tried to free the variable temp before and after releasing dict . char* string = "dummy-string"; xpc_object_t dict = xpc_dictionary_create(NULL, NULL, 0); xpc_dictionary_set_string(dict, "str", string); const char* temp = xpc_dictionary_get_string(dict, "str"); printf("temp before release: %s\n", temp); free((void *)temp); // case 1 xpc_release(dict); // free((void *)temp); // case 2 printf("temp after release: %s\n", temp); in both the cases i got the output: # temp before release: dummy-string # app(18502,0x1f02fc840) malloc: Double free of object 0x145004a20 # app(18502,0x1f02fc840) malloc: *** set a breakpoint in malloc_error_break to debug # SIGABRT: abort # PC=0x186953720 m=0 sigcode=0 # signal arrived during cgo execution # ... # ...

I am trying to migrate a WatchConnectivity App to Swift6 and I found an Issue with my replyHandler callback for sendMessageData. I am wrapping sendMessageData in withCheckedThrowingContinuation, so that I can await the response of the reply. I then update a Main Actor ObservableObject that keeps track of the count of connections that have not replied yet, before returning the data using continuation.resume. ... @preconcurrency import WatchConnectivity actor ConnectivityManager: NSObject, WCSessionDelegate { private var session: WCSession = .default private let connectivityMetaInfoManager: ConnectivityMetaInfoManager ... private func sendMessageData(_ data: Data) async throws -> Data? { Logger.shared.debug("called on Thread \(Thread.current)") await connectivityMetaInfoManager.increaseOpenSendConnectionsCount() return try await withCheckedThrowingContinuation({ continuation in self.session.sendMessageData( data, replyHandler: { data in Task { await self.connectivityMetaInfoManager .decreaseOpenSendConnectionsCount() } continuation.resume(returning: data) }, errorHandler: { (error) in Task { await self.connectivityMetaInfoManager .decreaseOpenSendConnectionsCount() } continuation.resume(throwing: error) } ) }) } Calling sendMessageData somehow causing the app to crash and display the debug message: Incorrect actor executor assumption. The code runs on swift 5 with SWIFT_STRICT_CONCURRENCY = complete. However when I switch to swift 6 the code crashes. I rebuilt a simple version of the App. Adding bit by bit until I was able to cause the crash. See Broken App Awaiting sendMessageData and wrapping it in a task and adding the @Sendable attribute to continuation, solve the crash. See Fixed App But I do not understand why yet. Is this intended behaviour? Should the compiler warn you about this? Is it a WatchConnectivity issue? I initially posted on forums.swift.org, but was told to repost here.

I need to check how long we can run an app in background which act as a consumer of data / control filter. What is the max time we get to run our app in background without any of these app strategies? https://developer.apple.com/documentation/backgroundtasks/choosing-background-strategies-for-your-app

I have been working on updating an old app that makes extensive use of Objective-C's NSTask. Now using Process in Swift, I'm trying to gather updates as the process runs, using readabilityHandler and availableData. However, my process tends to exit before all data has been read. I found this post entitled "Running a Child Process with Standard Input and Output" but it doesn't seem to address gathering output from long-running tasks. Is there a straightforward way to gather ongoing output from a long running task without it prematurely exiting?

Hello, My team has developed a DNS proxy for macOS. We have this set up with a system extension that interacts with the OS, and an always-running daemon that does all the heavy lifting. Communication between the two is DNS request and response packet traffic. With this architecture what are best practices for how the system extension communicates with a daemon? We tried making the daemon a socket server, but the system extension could not connect to it. We tried using XPC but it did not work and we could not understand the errors that were returned. So what is the best way to do this sort of thing?

Hi, I have a sandboxed app with a bundled sandboxed XPC service. When it’s launched, the XPC service registers a repeating XPC activity with the system. The activity’s handler block does get called regularly like I’d expect, but it stops being called once the main app terminates. What’s the recommended way to fix this issue? Could I have a bundled XPC service double as a launch agent, or would that cause other problems?

I am developing a background application that acts as a metadata server under MacOS written in Swift. Sandboxed clients prompt the user to select URLs which are passed to the server as security scoped bookmarks via an App Group and the metadata will be passed back. I don't want the I/O overhead of passing the complete image file data to the server. All the variations I have tried of creating security scoped bookmarks in the client and reading them from the server fail with error messages such as "The file couldn’t be opened because it isn’t in the correct format." Can anyone guide me in the right direction or is this just not possible?

After logging in to the main App, turn on screen recording, then switch to the interface of another App to perform operations. After about ten-odd minutes, when returning to the main App, it was found that the app was forcefully quit by the system, and subsequent operations could not be carried out.

Hi, I have a couple questions about background app refresh. First, is the function RefreshAppContentsOperation() where to implement code that needs to be run in the background? Second, despite importing BackgroundTasks, I am getting the error "cannot find operationQueue in scope". What can I do to resolve that? Thank you. func scheduleAppRefresh() { let request = BGAppRefreshTaskRequest(identifier: "peaceofmindmentalhealth.RoutineRefresh") // Fetch no earlier than 15 minutes from now. request.earliestBeginDate = Date(timeIntervalSinceNow: 15 * 60) do { try BGTaskScheduler.shared.submit(request) } catch { print("Could not schedule app refresh: \(error)") } } func handleAppRefresh(task: BGAppRefreshTask) { // Schedule a new refresh task. scheduleAppRefresh() // Create an operation that performs the main part of the background task. let operation = RefreshAppContentsOperation() // Provide the background task with an expiration handler that cancels the operation. task.expirationHandler = { operation.cancel() } // Inform the system that the background task is complete // when the operation completes. operation.completionBlock = { task.setTaskCompleted(success: !operation.isCancelled) } // Start the operation. operationQueue.addOperation(operation) } func RefreshAppContentsOperation() -> Operation { }

Is the title possible ? I tried [[thread valueForKey:@"_private"] valueForKey:@"tid"] but the tid was not kvc compliant. private apis are alright because this is just for testing remote process thread creation. I already have a working method but it has hardcoded assembly so you can't do anything else. this question is mainly for Quinn (figured he may know something about this)

Hi, I built an Electron app that uses puppeteer-cluster to open a bundled version of Chrome. Everything works before packaging/signing with electron builder. Transporter does not report any issues and the app opens in TestFlight. the Chrome.app is signed separately before running builder hardenedRuntime = false However, a permission error occurs when cluster attempts to launch Chrome: Error: Unable to launch browser, error message: Failed to launch the browser process! [0601/152740.225314:ERROR:bootstrap.cc(65)] bootstrap_check_in org.chromium.crashpad.child_port_handshake.9915.63117.BUEXLMXFWPLCEONM: Permission denied (1100) [0601/152740.226091:ERROR:file_io.cc(94)] ReadExactly: expected 4, observed 0 [0601/152740.229808:ERROR:bootstrap.cc(65)] bootstrap_check_in org.chromium.crashpad.child_port_handshake.9913.63115.VVKELOQUCWUYPFMQ: Permission denied (1100) [0601/152740.230244:ERROR:file_io.cc(94)] ReadExactly: expected 4, observed 0 [9911:45571:0601/152740.506968:ERROR:named_platform_channel_mac.cc(44)] bootstrap_check_in com.google.chrome.for.testing.apps.52995c87946bbcc94fc9a27df1478a13: Permission denied (1100) [9911:62467:0601/152740.507564:FATAL:mach_port_rendezvous.cc(281)] Check failed: kr == KERN_SUCCESS. bootstrap_check_in com.google.chrome.for.testing.MachPortRendezvousServer.9911: Permission denied (1100) at Cluster.<anonymous> (/Applications/MyApp.app/Contents/Resources/app.asar/node_modules/puppeteer-cluster/dist/Cluster.js:119:23) at Generator.throw (<anonymous>) at rejected (/Applications/MyApp.app/Contents/Resources/app.asar/node_modules/puppeteer-cluster/dist/Cluster.js:6:65) at process.processTicksAndRejections (node:internal/process/task_queues:105:5) I'm wondering if it's an issue with entitlements, or something more. The entitlements.mas.plist (aside from identifiers): com.apple.security.app-sandbox com.apple.security.cs.allow-jit com.apple.security.cs.allow-unsigned-executable-memory com.apple.security.cs.allow-dyld-environment-variables com.apple.security.network.client com.apple.security.network.server com.apple.security.files.user-selected.read-write com.apple.security.cs.disable-executable-page-protection com.apple.security.files.user-selected.executable I've spent many hours searching for a solution. Any help or insight would be greatly appreciated.

I have an app which contains a bundled launch agent that I register using SMAppService.agent(plistName:). I’ve packaged the launch agent executable in the typical Mac app bundle structure so I can embed a framework in it. So, the launch agent lives in Contents/SharedSupport/MyLaunchAgent.app/Contents/MacOS/MyLaunchAgent. However, I suspect this approach might be falling afoul of the scheduler, since the taskinfo tool reports my launch agent has a requested & effective role of TASK_DEFAULT_APPLICATION (PRIO_DARWIN_ROLE_UI), rather than the TASK_UNSPECIFIED (PRIO_DARWIN_ROLE_DEFAULT) value I see with system daemons. I tried setting the LSUIElement Info.plist key of my launch agent to YES, but this seems to have had no effect. What’s the recommended approach here?

I’m looking for an authoritative answer on how BGAppRefreshTask behaves after a user force-quits an app (swipes it away in the App Switcher). My app relies on early-morning background refresh to prepare and schedule notifications based on user-defined thresholds and weather forecasts. Behavior across devices seems inconsistent, however: sometimes a scheduled background refresh still runs, and other times it appears completely blocked. Apple’s documentation doesn’t clearly state what should happen, and developer discussions conflict. Could someone from Apple please clarify: Will a previously scheduled BGAppRefreshTask run after the user force-quits the app? If not, is there a recommended alternative for time-sensitive updates that must schedule user alerts? What is the expected system behavior regarding the predictability of background refresh after a force-quit? A definitive answer would help ensure the app aligns with intended system behavior. Thanks!

Are there any plans to add RBI support (the sending keyword) to the OSAllocatedLock interface? So it could be used with non-sendable objects without surrendering to the unchecked API

For a macOS GUI application (with a UIKit or AppKit entry point), I want to reliably capture diagnostic logs sent to stderr — especially useful when the app is launched from a terminal script or runs in the background, and traditional GUI elements (like alert dialogs) may not be viable. This is to log startup failures or even success messages for later inspection. However, when the app is launched via open MyApp.app, stderr redirection like open MyApp.app 2> log.txt does not capture any output — the file is created, but remains empty. The only way I can capture stderr reliably is by bypassing the bundle and directly launching the binary inside with ./MyApp.app/Contents/MacOS/MyApp 2> ~/log.txt This logs as expected, but is not the user-friendly or typical way to launch apps on macOS. Double-clicking the app in Finder also does not show any stderr output. Is there any recommended or supported way to redirect or access stderr output when launching a .app bundle via open, or any best practice for logging critical failures from a GUI app when terminal output isn't visible?

I’ve been experimenting with Dispatch, and workloops in particular. I gather that they’re similar to serial queues, except that they reorder work items by QoS. I suspect there’s more to workloops than meets the eye, though; calling dispatch_set_target_queue on them has no effect, in spite of the <dispatch/workloop.h> saying that workloops “can be passed to all APIs accepting a dispatch queue, except for functions from the dispatch_sync() family”. Workloops keep showing up in odd places like Metal and Network.framework backtraces, and <dispatch/workloop.h> includes functionality for tying workloops to os_workgroups (?!). What exactly is a workloop beyond just a serial queue with priority ordering, and why can’t I set the target queue of one?

For some reason, after invoking an unrelated dlclose() call to unload any .dylib that had previously been loaded via dlopen(..., RTLD_NOW), the subsequent call to task_info(mach_task_self(), TASK_DYLD_INFO, ...) syscall returns unexpected structure in dyld_uuid_info image_infos-&gt;uuidArray, that, while it seems to represent an array of struct dyld_uuid_info elements, there is only 1 such element (dyld_all_image_infos *infos-&gt;uuidArrayCount == 1) and the app crashes when trying to access dyld_uuid_info image-&gt;imageLoadAddress-&gt;magic, as image-&gt;imageLoadAddress doesn't seem to represent a valid struct mach_header structure address (although it looks like a normal pointer within the process address space. What does it point to?). This reproduces on macOS 15.4.1 (24E263) Could you please confirm that this is a bug in the specified OS build, or point to incorrect usage of the task_info() API? Attaching the C++ file that reproduces the issue to this email message It needs to be built on macOS 15.4.1 (24E263) via Xcode or just a command line clang++ compiler. It may crash or return garbage, depending on memory layout, but on this macOS build it doesn’t return a correct feedfacf magic number for the struct mach_header structure. Thank you Feedback Assistant reference: FB18431345 //On `macOS 15.4.1 (24E263)` create a C++ application (for example, in Xcode), with the following contents. Note, that this application should crash on this macOS build. It will not crash, however, if you either: //1. Comment out `dlclose()` call //2. Change the order of the `performDlOpenDlClose()` and `performTaskInfoSyscall()` functions calls (first performTaskInfoSyscall() then performDlOpenDlClose()). #include &lt;iostream&gt; #include &lt;dlfcn.h&gt; #include &lt;mach/mach.h&gt; #include &lt;mach-o/dyld_images.h&gt; #include &lt;mach-o/loader.h&gt; void performDlOpenDlClose() { printf("dlopen/dlclose function\n"); printf("Note: please adjust the path below to any real dylib on your system, if the path below doesn't exist!\n"); std::string path = "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/libswiftDemangle.dylib"; printf("Dylib to open: %s\n", path.c_str()); void* handle = ::dlopen(path.c_str(), RTLD_NOW); if(handle) { ::dlclose(handle); } else { printf("Error: %s\n", dlerror()); } } void performTaskInfoSyscall() { printf("Making a task_info() syscall\n"); printf("\033[34mSource File: %s\033[0m\n", __FILE__); task_t task = mach_task_self(); struct task_dyld_info dyld_info; mach_msg_type_number_t size = TASK_DYLD_INFO_COUNT; kern_return_t kr = task_info(task, TASK_DYLD_INFO, (task_info_t)&amp;dyld_info, &amp;size); if (kr != KERN_SUCCESS) { fprintf(stderr, "task_info failed: %s\n", mach_error_string(kr)); } const struct dyld_all_image_infos* infos = (const struct dyld_all_image_infos*)dyld_info.all_image_info_addr; printf("version: %d, infos-&gt;infoArrayCount: %d\n", infos-&gt;version, infos-&gt;infoArrayCount); for(uint32_t i=0; i&lt;infos-&gt;infoArrayCount; i++) { dyld_image_info image = infos-&gt;infoArray[i]; const struct mach_header* header = image.imageLoadAddress; printf("%d ", i); printf("%p ", (void*)image.imageLoadAddress); printf("(%x) ", header-&gt;magic); printf("%s\n", image.imageFilePath); fflush(stdout); } printf("\n\n"); printf("infos-&gt;uuidArrayCount: %lu\n", infos-&gt;uuidArrayCount); for(uint32_t i=0; i&lt;infos-&gt;uuidArrayCount; i++) { dyld_uuid_info image = infos-&gt;uuidArray[i]; const struct mach_header* header = image.imageLoadAddress; printf("%d ", i); printf("%p ", (void*)image.imageLoadAddress); printf("(%x)\n", header-&gt;magic); fflush(stdout); } printf("task_info() syscall result processing is completed\n\n"); } int main(int argc, const char * argv[]) { performDlOpenDlClose(); performTaskInfoSyscall(); return 0; }

Hello, My app (daemon) time to time need to know list of GUI login sessions. According to the recommendation, I am using getutxent(). https://developer.apple.com/library/archive/qa/qa1133/_index.html However, I have faced with unclear behaviour in case of running "Migration Assistant". It can be re-created without my app. Steps to recreate: login as 'user #1' start "Migration Assistant" quit "Migration Assistant" new login prompt will be opened login as 'user #2' In spite the session of 'user #1' is closed, the command line tool "who", which gathers information from /var/run/utmpx, reports opened sessions of 'user #1'. Is it bug or feature? Thank you in advance!