Search results for

“LLDB crash”

30,542 results found

Post

Replies

Boosts

Views

Activity

AVCapturePhotoOutput crashes at delegate callback on MacOS 13.7.5
A functioning Multiplatform app, which includes use of Continuity Camera on an M1MacMini running Sequoia 15.5, works correctly capturing photos with AVCapturePhoto. However, that app (and a test app just for Continuity Camera) crashes at delegate callback when run on a 2017 MacBookPro under MacOS 13.7.5. The app was created with Xcode 16 (various releases) and using Swift 6 (but tried with 5). Compiling and running the test app with Xcode 15.2 on the 13.7.5 machine also crashes at delegate callback. The iPhone 15 Continuity Camera gets detected and set up correctly, and preview video works correctly. It's when the CapturePhoto code is run that the crash occurs. The relevant capture code is: func capturePhoto() { let captureSettings = AVCapturePhotoSettings() captureSettings.flashMode = .auto photoOutput.maxPhotoQualityPrioritization = .quality photoOutput.capturePhoto(with: captureSettings, delegate: PhotoDelegate.shared) print(**** CameraManager: capturePhoto) } and the delegate ca
1
0
504
Nov ’25
Error accessing backing data on deleted item in detached task
I have been working on an app for the past few months, and one issue that I have encountered a few times is an error where quick subsequent deletions cause issues with detached tasks that are triggered from some user actions. Inside a Task.detached, I am building an isolated model context, querying for LineItems, then iterating over those items. The crash happens when accessing a Transaction property through a relationship. var byTransactionId: [UUID: [LineItem]] { return Dictionary(grouping: self) { item in item.transaction?.id ?? UUID() } } In this case, the transaction has been deleted, but the relationship existed when the fetch occurred, so the transaction value is non-nil. The crash occurs when accessing the id. This is the error. SwiftData/BackingData.swift:1035: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdenti
3
0
384
Nov ’25
Container Failing to Initialize After a Successful Migration & Initialization
I'm experiencing the following error with my SwiftData container when running a build: Code=134504 Cannot use staged migration with an unknown model version. Code Structure - Summary I am using a versionedSchema to store multiple models in SwiftData. I started experiencing this issue when adding two new models in the newest Schema version. Starting from the current public version, V4.4.6, there are two migrations. Migration Summary The first migration is to V4.4.7. This is a lightweight migration removing one attribute from one of the models. This was tested and worked successfully. The second migration is to V5.0.0. This is a custom migration adding two new models, and instantiating instances of the two new models based on data from instances of the existing models. In the initial testing of this version, no issues were observed. Issue and Steps to Reproduce Reproduction of issue: Starting from a fresh build of the publicly released V4.4.6, I run a new build that contains both Schema Versions (V4.4.7 and V5.
2
0
722
Nov ’25
App mysteriously crashing in CFNetwork.LoaderQ queue
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. S
6
0
4.3k
Nov ’25
Xcode 26.1 / OS 26.1 regression with schema and macros
After Xcode 26.1 was updated and installing the OS 26.1 simulators, my app started crashing related to transformable properties. When I checked my schema, I noticed that properties with array collection types are suddenly set with an option transformable with Optional(NSSecureUnarchiveFromData)], even though I do not use any transformable types. I verified the macros, no transformable was specified. This is causing ModelCoders to encode/decode my properties incorrectly. This is not an issue when I switch back to OS 26.0 simulators.
4
0
457
Nov ’25
UIDocument crashes when overriding writeContents(_:) in Swift 6
I’ve been trying to set up a UIDocument and override writeContents(...). This works correctly in older projects, but I haven’t been able to get it working in my new iOS 26 app using Swift 6. To troubleshoot, I tested the Particles demo and successfully overrode writeContents there. However, as soon as I switch that project to iOS 26 and Swift 6, calling save; which triggers writeContents, causes the same crash. override public func writeContents( _ data: Any, to url: URL, for _: UIDocument.SaveOperation, originalContentsURL _: URL?, ) throws { ... } Thread 10 Queue : UIDocument File Access (serial)
Topic: UI Frameworks SubTopic: UIKit
1
0
95
Nov ’25
Sign in with Apple error reported by App Review, but impossible to reproduce (iPadOS 26.1)
Hi everyone, I’m currently facing a blocking issue during App Review, and I’d really appreciate some help from anyone who has experienced something similar. My app was rejected under Guideline 2.1 – App Completeness with the following message: “An error message appeared after trying to Sign in with Apple. Device: iPad Air (5th generation), iPadOS 26.1.” The problem is: I cannot reproduce this bug at all, even when testing under the same conditions. ✔ What I tested: Physical iPad Air M2 on iPadOS 26.1 Physical iPhone devices iOS/iPadOS simulators (latest Xcode) TestFlight build (clean install) Debug build installed via Xcode (device connected) In every case, Sign in with Apple works correctly: Authentication sheet displays properly Callback returns the credential User is created/logged in without error No crash, no rejected promise, no empty credential ✔ Environment Using ASAuthorizationAppleIDProvider + ASAuthorizationController Default Apple Sign In button No custom nonce/redirect modifications No b
1
0
186
Nov ’25
Reply to NotificationCenter Crash On iOS 18+ Swift6.2
You were right. We've found out that the issue was that we registered an observer with addObserver using a #selector that pointed to a function marked as @MainActor, but we were calling the NotificationCenter.post method from a background thread. Apparently this caused the main-actor isolation check to fail, which led to a crash. Even though there is no data-race or UI operation in the function, looks like it is enough for the function to be @MainActor to cause a crash when called from outside the main thread. We fixed it by making sure the relevant NotificationCenter.post calls are executed on the main thread. Initially, we thought that marking the function with @MainActor would prevent it from being called from a nonisolated context by producing a compile-time error in Swift 6 mode. But since a Selector instance is not aware of the actor isolation of the target function, Xcode is not able to show a warning and it caused us to not realize the issue at first. I appreciate your guidance @DTS
Topic: Programming Languages SubTopic: Swift Tags:
Nov ’25
NotificationCenter Crash On iOS 18+ Swift6.2
After switching our iOS app project from Swift 5 to Swift 6 and publishing an update, we started seeing a large number of crashes in Firebase Crashlytics. The crashes are triggered by NotificationCenter methods (post, addObserver, removeObserver) and show the following error: BUG IN CLIENT OF LIBDISPATCH: Assertion failed: Block was expected to execute on queue [com.apple.main-thread (0x1f9dc1580)] All scopes to related calls are already explicitly marked with @MainActor. This issue never occurred with Swift 5, but appeared immediately after moving to Swift 6. Has anyone else encountered this problem? Is there a known solution or workaround? Thanks in advance!
2
0
1.6k
Nov ’25
Reply to SwiftData: This model instance was invalidated because its backing data could no longer be found the store
Hello @joadan, I made the sample as is to illustrate that may be the user will touch the mainContext to delete objects (by touching a user interface) even if a ModelActor exists. But may be that’s another topic. I update my sample and just tried using modelContext in delete and removing @MainActor but as you guess, still crashing. However manually clearing the self._rooms property (~= deleteV1) or even setting explicitly nil the home property of my rooms before deleting, avoid the crash. When you say « you have a reference to the deleted objects in self._rooms that you need to clear before doing the delete. » This seems to be obvious to you can you detail a bit ? I guess this is pretty common scenario where an object like a view retain some models. Why does keeping a reference to homes is ok, rooms ok but both leads to a crash?
Nov ’25
SwiftData: This model instance was invalidated because its backing data could no longer be found the store
Hello 👋, I encounter the This model instance was invalidated because its backing data could no longer be found the store crash with SwiftData. Which from what I understood means I try to access a model after it has been removed from the store (makes sense). I made a quick sample to reproduce/better understand because there some case(s) I can't figure it out. Let's take a concrete example, we have Home model and a Home can have many Room(s). // Sample code @MainActor let foo = Foo() // A single reference let database = Database(modelContainer: sharedModelContainer) // A single reference @MainActor class Foo { // Properties to explicilty keep reference of model(s) for the purpose of the POC var _homes = [Home]() var _rooms = [Room]() func fetch() async { let homes = await database.fetch().map { sharedModelContainer.mainContext.model(for: $0) as! Home } print(ObjectIdentifier(homes[0]), homes[0].rooms?.map(.id)) // This will crash here or not. } // Same version of a delete function with subtle
2
0
274
Nov ’25
Reply to SwiftData: This model instance was invalidated because its backing data could no longer be found the store
When you are using @ModelActor you have access to a specific model context for that actor via the property modelContext so you should have try modelContext.delete(… and you should definitely not use the context from the main actor in any other actor. This alone will probably not fix the crash since you have a reference to the deleted objects in self._rooms that you need to clear before doing the delete.
Nov ’25
Reply to Weird crash: missing symbol Swift.AsyncIteratorProtocol.next()
I ran into this exact issue on iOS 18.0–18.3. In my case it was triggered by how I implemented the AsyncSequence / AsyncIteratorProtocol. I had custom iterators that only implemented the new typed-throws overload: mutating func next(isolation actor: isolated (any Actor)?) async throws(Self.Failure) -> Self.Element? The fix for me was to also implement the original next() overload and forward it into the newer one: public mutating func next() async throws -> Element? { try await next(isolation: #isolation) } Once I added this overload, the app ran without crashing on all affected 18.x versions, and the iterator still correctly routed calls into the newer next(isolation:) implementation. Hope this helps someone else running into the same issue.
Topic: App & System Services SubTopic: Core OS Tags:
Nov ’25
Weird crash: missing symbol Swift.AsyncIteratorProtocol.next()
I got several reports about our TestFlight app crashing unconditionally on 2 devices (iOS 18.1 and iOS 18.3.1) on app start with the following reason: Termination Reason: DYLD 4 Symbol missing Symbol not found: _$sScIsE4next7ElementQzSgyYa7FailureQzYKF (terminated at launch; ignore backtrace) The symbol in question demangles to (extension in Swift):Swift.AsyncIteratorProtocol.next() async throws(A.Failure) -> A.Element? Our deploy target is iOS 18.0, this symbol was introduced in Swift 6.0, we're using latest Xcode 16 now - everything should be working, but for some reason aren't. Since this symbol is quite rarely used directly, I was able to pinpoint the exact place in code related to it. Few days ago I added the following code to our app library (details omitted): public struct AsyncRecoveringStream: AsyncSequence { ... public struct AsyncIterator: AsyncIteratorProtocol { ... public mutating func next(isolation actor: isolated (any Actor)? = #isolation) async throws(Failure) -> Element? { ...
3
0
429
Nov ’25
AVCapturePhotoOutput crashes at delegate callback on MacOS 13.7.5
A functioning Multiplatform app, which includes use of Continuity Camera on an M1MacMini running Sequoia 15.5, works correctly capturing photos with AVCapturePhoto. However, that app (and a test app just for Continuity Camera) crashes at delegate callback when run on a 2017 MacBookPro under MacOS 13.7.5. The app was created with Xcode 16 (various releases) and using Swift 6 (but tried with 5). Compiling and running the test app with Xcode 15.2 on the 13.7.5 machine also crashes at delegate callback. The iPhone 15 Continuity Camera gets detected and set up correctly, and preview video works correctly. It's when the CapturePhoto code is run that the crash occurs. The relevant capture code is: func capturePhoto() { let captureSettings = AVCapturePhotoSettings() captureSettings.flashMode = .auto photoOutput.maxPhotoQualityPrioritization = .quality photoOutput.capturePhoto(with: captureSettings, delegate: PhotoDelegate.shared) print(**** CameraManager: capturePhoto) } and the delegate ca
Replies
1
Boosts
0
Views
504
Activity
Nov ’25
Error accessing backing data on deleted item in detached task
I have been working on an app for the past few months, and one issue that I have encountered a few times is an error where quick subsequent deletions cause issues with detached tasks that are triggered from some user actions. Inside a Task.detached, I am building an isolated model context, querying for LineItems, then iterating over those items. The crash happens when accessing a Transaction property through a relationship. var byTransactionId: [UUID: [LineItem]] { return Dictionary(grouping: self) { item in item.transaction?.id ?? UUID() } } In this case, the transaction has been deleted, but the relationship existed when the fetch occurred, so the transaction value is non-nil. The crash occurs when accessing the id. This is the error. SwiftData/BackingData.swift:1035: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdenti
Replies
3
Boosts
0
Views
384
Activity
Nov ’25
Container Failing to Initialize After a Successful Migration & Initialization
I'm experiencing the following error with my SwiftData container when running a build: Code=134504 Cannot use staged migration with an unknown model version. Code Structure - Summary I am using a versionedSchema to store multiple models in SwiftData. I started experiencing this issue when adding two new models in the newest Schema version. Starting from the current public version, V4.4.6, there are two migrations. Migration Summary The first migration is to V4.4.7. This is a lightweight migration removing one attribute from one of the models. This was tested and worked successfully. The second migration is to V5.0.0. This is a custom migration adding two new models, and instantiating instances of the two new models based on data from instances of the existing models. In the initial testing of this version, no issues were observed. Issue and Steps to Reproduce Reproduction of issue: Starting from a fresh build of the publicly released V4.4.6, I run a new build that contains both Schema Versions (V4.4.7 and V5.
Replies
2
Boosts
0
Views
722
Activity
Nov ’25
App mysteriously crashing in CFNetwork.LoaderQ queue
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. S
Replies
6
Boosts
0
Views
4.3k
Activity
Nov ’25
Reply to App mysteriously crashing in CFNetwork.LoaderQ queue
Hi @vojta.bohm, Did the fix solve the crash ?
Topic: Programming Languages SubTopic: Swift Tags:
Replies
Boosts
Views
Activity
Nov ’25
Xcode 26.1 / OS 26.1 regression with schema and macros
After Xcode 26.1 was updated and installing the OS 26.1 simulators, my app started crashing related to transformable properties. When I checked my schema, I noticed that properties with array collection types are suddenly set with an option transformable with Optional(NSSecureUnarchiveFromData)], even though I do not use any transformable types. I verified the macros, no transformable was specified. This is causing ModelCoders to encode/decode my properties incorrectly. This is not an issue when I switch back to OS 26.0 simulators.
Replies
4
Boosts
0
Views
457
Activity
Nov ’25
UIDocument crashes when overriding writeContents(_:) in Swift 6
I’ve been trying to set up a UIDocument and override writeContents(...). This works correctly in older projects, but I haven’t been able to get it working in my new iOS 26 app using Swift 6. To troubleshoot, I tested the Particles demo and successfully overrode writeContents there. However, as soon as I switch that project to iOS 26 and Swift 6, calling save; which triggers writeContents, causes the same crash. override public func writeContents( _ data: Any, to url: URL, for _: UIDocument.SaveOperation, originalContentsURL _: URL?, ) throws { ... } Thread 10 Queue : UIDocument File Access (serial)
Topic: UI Frameworks SubTopic: UIKit
Replies
1
Boosts
0
Views
95
Activity
Nov ’25
Sign in with Apple error reported by App Review, but impossible to reproduce (iPadOS 26.1)
Hi everyone, I’m currently facing a blocking issue during App Review, and I’d really appreciate some help from anyone who has experienced something similar. My app was rejected under Guideline 2.1 – App Completeness with the following message: “An error message appeared after trying to Sign in with Apple. Device: iPad Air (5th generation), iPadOS 26.1.” The problem is: I cannot reproduce this bug at all, even when testing under the same conditions. ✔ What I tested: Physical iPad Air M2 on iPadOS 26.1 Physical iPhone devices iOS/iPadOS simulators (latest Xcode) TestFlight build (clean install) Debug build installed via Xcode (device connected) In every case, Sign in with Apple works correctly: Authentication sheet displays properly Callback returns the credential User is created/logged in without error No crash, no rejected promise, no empty credential ✔ Environment Using ASAuthorizationAppleIDProvider + ASAuthorizationController Default Apple Sign In button No custom nonce/redirect modifications No b
Replies
1
Boosts
0
Views
186
Activity
Nov ’25
Reply to NotificationCenter Crash On iOS 18+ Swift6.2
You were right. We've found out that the issue was that we registered an observer with addObserver using a #selector that pointed to a function marked as @MainActor, but we were calling the NotificationCenter.post method from a background thread. Apparently this caused the main-actor isolation check to fail, which led to a crash. Even though there is no data-race or UI operation in the function, looks like it is enough for the function to be @MainActor to cause a crash when called from outside the main thread. We fixed it by making sure the relevant NotificationCenter.post calls are executed on the main thread. Initially, we thought that marking the function with @MainActor would prevent it from being called from a nonisolated context by producing a compile-time error in Swift 6 mode. But since a Selector instance is not aware of the actor isolation of the target function, Xcode is not able to show a warning and it caused us to not realize the issue at first. I appreciate your guidance @DTS
Topic: Programming Languages SubTopic: Swift Tags:
Replies
Boosts
Views
Activity
Nov ’25
NotificationCenter Crash On iOS 18+ Swift6.2
After switching our iOS app project from Swift 5 to Swift 6 and publishing an update, we started seeing a large number of crashes in Firebase Crashlytics. The crashes are triggered by NotificationCenter methods (post, addObserver, removeObserver) and show the following error: BUG IN CLIENT OF LIBDISPATCH: Assertion failed: Block was expected to execute on queue [com.apple.main-thread (0x1f9dc1580)] All scopes to related calls are already explicitly marked with @MainActor. This issue never occurred with Swift 5, but appeared immediately after moving to Swift 6. Has anyone else encountered this problem? Is there a known solution or workaround? Thanks in advance!
Replies
2
Boosts
0
Views
1.6k
Activity
Nov ’25
Reply to SwiftData: This model instance was invalidated because its backing data could no longer be found the store
Hello @joadan, I made the sample as is to illustrate that may be the user will touch the mainContext to delete objects (by touching a user interface) even if a ModelActor exists. But may be that’s another topic. I update my sample and just tried using modelContext in delete and removing @MainActor but as you guess, still crashing. However manually clearing the self._rooms property (~= deleteV1) or even setting explicitly nil the home property of my rooms before deleting, avoid the crash. When you say « you have a reference to the deleted objects in self._rooms that you need to clear before doing the delete. » This seems to be obvious to you can you detail a bit ? I guess this is pretty common scenario where an object like a view retain some models. Why does keeping a reference to homes is ok, rooms ok but both leads to a crash?
Replies
Boosts
Views
Activity
Nov ’25
SwiftData: This model instance was invalidated because its backing data could no longer be found the store
Hello 👋, I encounter the This model instance was invalidated because its backing data could no longer be found the store crash with SwiftData. Which from what I understood means I try to access a model after it has been removed from the store (makes sense). I made a quick sample to reproduce/better understand because there some case(s) I can't figure it out. Let's take a concrete example, we have Home model and a Home can have many Room(s). // Sample code @MainActor let foo = Foo() // A single reference let database = Database(modelContainer: sharedModelContainer) // A single reference @MainActor class Foo { // Properties to explicilty keep reference of model(s) for the purpose of the POC var _homes = [Home]() var _rooms = [Room]() func fetch() async { let homes = await database.fetch().map { sharedModelContainer.mainContext.model(for: $0) as! Home } print(ObjectIdentifier(homes[0]), homes[0].rooms?.map(.id)) // This will crash here or not. } // Same version of a delete function with subtle
Replies
2
Boosts
0
Views
274
Activity
Nov ’25
Reply to SwiftData: This model instance was invalidated because its backing data could no longer be found the store
When you are using @ModelActor you have access to a specific model context for that actor via the property modelContext so you should have try modelContext.delete(… and you should definitely not use the context from the main actor in any other actor. This alone will probably not fix the crash since you have a reference to the deleted objects in self._rooms that you need to clear before doing the delete.
Replies
Boosts
Views
Activity
Nov ’25
Reply to Weird crash: missing symbol Swift.AsyncIteratorProtocol.next()
I ran into this exact issue on iOS 18.0–18.3. In my case it was triggered by how I implemented the AsyncSequence / AsyncIteratorProtocol. I had custom iterators that only implemented the new typed-throws overload: mutating func next(isolation actor: isolated (any Actor)?) async throws(Self.Failure) -> Self.Element? The fix for me was to also implement the original next() overload and forward it into the newer one: public mutating func next() async throws -> Element? { try await next(isolation: #isolation) } Once I added this overload, the app ran without crashing on all affected 18.x versions, and the iterator still correctly routed calls into the newer next(isolation:) implementation. Hope this helps someone else running into the same issue.
Topic: App & System Services SubTopic: Core OS Tags:
Replies
Boosts
Views
Activity
Nov ’25
Weird crash: missing symbol Swift.AsyncIteratorProtocol.next()
I got several reports about our TestFlight app crashing unconditionally on 2 devices (iOS 18.1 and iOS 18.3.1) on app start with the following reason: Termination Reason: DYLD 4 Symbol missing Symbol not found: _$sScIsE4next7ElementQzSgyYa7FailureQzYKF (terminated at launch; ignore backtrace) The symbol in question demangles to (extension in Swift):Swift.AsyncIteratorProtocol.next() async throws(A.Failure) -> A.Element? Our deploy target is iOS 18.0, this symbol was introduced in Swift 6.0, we're using latest Xcode 16 now - everything should be working, but for some reason aren't. Since this symbol is quite rarely used directly, I was able to pinpoint the exact place in code related to it. Few days ago I added the following code to our app library (details omitted): public struct AsyncRecoveringStream: AsyncSequence { ... public struct AsyncIterator: AsyncIteratorProtocol { ... public mutating func next(isolation actor: isolated (any Actor)? = #isolation) async throws(Failure) -> Element? { ...
Replies
3
Boosts
0
Views
429
Activity
Nov ’25