withCheckedContinuation crashes on Xcode 16 RC #75952

MarkVillacampa · 2024-08-19T13:09:14Z

Description

I can reproduce on Xcode 16 RC and Xcode 16.1 beta, but ONLY when running the app as "Designed for iPhone/iPad" on macOS Sonoma, and ONLY in debug mode (crash goes away in release mode).

I cannot reproduce by running on iOS 17 or 18 neither device nor simulator, and cannot reproduce either when running on macOS Sequoia beta.

Some developers have reported the issue also reproduces when installing the app via TestFlight on an iOS 18 device.

Original issue: RevenueCat/purchases-ios#4177

FB14855530

Reproduction

_ = try await withCheckedContinuation { continuation in
    continuation.resume(returning: true)
}

Stack dump

Thread 0 Crashed:
0   asdfsadf.debug.dylib          	       0x102551354 withCheckedContinuation<A>(isolation:function:_:) + 232
1   asdfsadf.debug.dylib          	       0x102551135 closure #1 in closure #2 in ContentView.body.getter + 1 (ContentView.swift:21)
2   asdfsadf.debug.dylib          	       0x102552299 partial apply for closure #1 in closure #2 in ContentView.body.getter + 1
3   libswift_Concurrency.dylib    	       0x2548aa0f9 completeTaskWithClosure(swift::AsyncContext*, swift::SwiftError*) + 1

Expected behavior

It doesnt crash

Environment

Xcode 16.1 beta 1

Apple Swift version 6.0 (swiftlang-6.0.0.7.6 clang-1600.0.24.1)
Target: arm64-apple-macosx14.0

Additional information

No response

The text was updated successfully, but these errors were encountered:

MarkVillacampa · 2024-08-21T07:32:13Z

Quick update:

Crash is still reproducible in Xcode 16 beta 6.
The crash happens with withCheckedThrowingContinuation as well:

_ = try await withCheckedThrowingContinuation { continuation in
    continuation.resume(returning: true)
}

mszyszylo · 2024-09-03T13:46:55Z

Same issue for me.

I'm on Xcode 16.1 beta.

App crashes like @MarkVillacampa described with only iOS 18 simulators.

Thread 1: EXC_BAD_ACCESS (code=1, address=0x4)

MarkVillacampa · 2024-09-09T20:25:35Z

The crash is still present in Xcode 16 RC when running a Debug build as "Designed for iPad/iPhone" on macOS Sonoma

random-yang · 2024-09-10T12:42:23Z

Has anyone posted a question on the Apple Developer Forum, and is there a final solution to the problem?

kiran-nayak-cheq · 2024-09-12T05:48:01Z

+1. Any update on this?

random-yang · 2024-09-13T05:30:03Z

@kiran-nayak-cheq
Looks like the issue has been fixed in the updated version?
https://developer.apple.com/forums/thread/761580
https://forums.developer.apple.com/forums/thread/762682?page=1#803104022

guidedways · 2024-09-17T04:57:05Z

We're seeing this for our publicly released apps using Xcode version 16.0 (16A242d) (published, final updates to App Store, not debug versions) where random users are seeing persistent crashes at launch and the stack traces are vague. We see the following in each of them though:

9   libswift_Concurrency.dylib    	       0x26737e8a5 completeTaskWithClosure(swift::AsyncContext*, swift::SwiftError*) + 1

We are personally unable to reproduce this in any environment (debug / release) or on any OS. The users experiencing this range from being on macOS 11 to macOS 15, and iOS 16 / 18. It could potentially be affecting all operating system versions but we are unable to say this with certainty. We are using Xcode 16 to compile our apps using Swift v5 (5.10, not 6). The last update posted from Xcode 15 does not exhibit this issue.

jshier · 2024-09-21T07:53:13Z

We're seeing something similar in Alamofire, but in withTaskCancellationHandler that wraps withCheckedContinuation. Switching to unsafe continuations or the deprecated vision of withTaskCancellationHandler had no effect.

sergiocampama · 2024-09-21T12:58:21Z

We saw similar things on our app but we were able to identify it only happening on iOS 18/macOS 15 betas that were before the RC builds for each platform. We've found 3 cases of users where this was fixed by updating to the actual RC builds for each platform.

We did not see this happening before iOS 18/macOS 15.

On iOS the crashes looked like SIGSEV 4 with the following line as the top stack. On macOS they looked like the signal in this report (maybe because it's on the simulator it matches the macOS crash signature)

‘‘‘
@_swiftmacro_7Copilot0022Controllersswift_tiAIefMX24_33_9isolationfMf.swift - Line 1
‘‘‘

I was not able to find this generated file anywhere.

tshortli · 2024-09-21T16:55:29Z

This is a known issue documented in the Xcode 16 release notes (search for 134793410). It was addressed on the release/6.0.1 branch here: [6.0.1] SILOptimizer: Allow inlining of transparent functions in @backDeployed thunks by tshortli · Pull Request #76218 · swiftlang/swift · GitHub. Designed for iPhone/iPad binaries built with debug optimizations and deployed to macOS Sonoma or earlier are affected.

abdorizak · 2024-10-10T08:13:56Z

I'm facing the same Thread 1: EXC_BAD_ACCESS (code=1, address=0x4) issue with Xcode Version 16.0 and iOS 18.0, but it only occurs on specific devices and isn't consistently reproducible. this crash seems to depend on the specific device or scenario. It would be great if this could be investigated further to understand the underlying cause and ensure stability.

I'm using Swift 5 with Xcode 16. Below is a sample code to demonstrate the issue:

import Alamofire
import Foundation

struct MyModel: Decodable {
    let id: Int
    let name: String
}

func fetchData() async -> Result<MyModel, Error> {
    return await AF.request("https://api.example.com/data")
        .response(MyModel.self)
}

extension DataRequest {
    @MainActor
    func response<T: Decodable>(_ t: T.Type) async -> Result<T, Error> {
        return await withCheckedContinuation { continuation in // Fails on here `EXC_BAD_ACCESS error` 
            responseData(queue: .main) { response in
                switch response.result {
                case .success(let data):
                    do {
                        let decoder = JSONDecoder()
                        let obj = try decoder.decode(t.self, from: data)
                        continuation.resume(returning: .success(obj))
                    } catch {
                        continuation.resume(returning: .failure(error))
                    }
                case .failure(let error):
                    continuation.resume(returning: .failure(error))
                }
            }
        }
    }
}

The crash occurs when navigating between screens while the API call is still in progress, which leads to an EXC_BAD_ACCESS error. This only seems to happen on specific devices running iOS 18.0, and it's not consistently reproducible.

guidedways · 2024-10-10T09:04:54Z

I'm facing the same Thread 1: EXC_BAD_ACCESS (code=1, address=0x4) issue with Xcode Version 16.0 and iOS 18.0, but it only occurs on specific devices and isn't consistently reproducible. this crash seems to depend on the specific device or scenario. It would be great if this could be investigated further to understand the underlying cause and ensure stability.

I'm using Swift 5 with Xcode 16. Below is a sample code to demonstrate the issue:

import Alamofire

import Foundation



struct MyModel: Decodable {

    let id: Int

    let name: String

}



func fetchData() async -> Result<MyModel, Error> {

    return await AF.request("https://api.example.com/data")

        .response(MyModel.self)

}



extension DataRequest {

    @MainActor

    func response<T: Decodable>(_ t: T.Type) async -> Result<T, Error> {

        return await withCheckedContinuation { continuation in // Fails on here `EXC_BAD_ACCESS error` 

            responseData(queue: .main) { response in

                switch response.result {

                case .success(let data):

                    do {

                        let decoder = JSONDecoder()

                        let obj = try decoder.decode(t.self, from: data)

                        continuation.resume(returning: .success(obj))

                    } catch {

                        continuation.resume(returning: .failure(error))

                    }

                case .failure(let error):

                    continuation.resume(returning: .failure(error))

                }

            }

        }

    }

}

The crash occurs when navigating between screens while the API call is still in progress, which leads to an EXC_BAD_ACCESS error. This only seems to happen on specific devices running iOS 18.0, and it's not consistently reproducible.

Check with these users, they are most likely on an older beta version of iOS 18. I can confirm all our users were on an older beta version and updating to the latest iOS version fixed these crashes for them.

DougGregor · 2024-11-08T19:30:54Z

This was addressed in Swift 6.0.1.

DougGregor · 2024-11-11T15:00:02Z

There is a similar issue that affects older iOS 18 betas. Those devices should really be updated to the iOS 18 release (or newer), but if you need an app-side workaround, see https://forums.swift.org/t/global-with-concurrency-functions-crash-on-catalyst-designed-for-ipad-on-macos/74823/13.

mike123789-dev · 2024-11-15T02:00:58Z

This was addressed in Swift 6.0.1.

hi! in our project we are still using swift5

does this mean that the fix will not be applied while targeting swift5?

thanks in advance

tshortli · 2024-11-15T02:06:47Z

No, this is a common source of confusion but the setting you have screenshot is the Swift "language mode". The language mode is independent of the version of the Swift compiler you are building with. Swift 6.0.1 refers to the version of the compiler.

mike123789-dev · 2024-11-15T04:51:41Z

@tshortli
i was worried that we will have to migrate a whole codebase to swift 6.

thanks for the reply

Lyine0924 · 2024-11-20T05:24:01Z

hello. I am still experiencing the same issue. Is anyone else having the same problem as me?
I deployed the app in the following environment

Environment

Xcode-16.1(16B40)
swift-driver version: 1.115 Apple Swift version 6.0.2 (swiftlang-6.0.2.1.2 clang-1600.0.26.4)
Target: arm64-apple-macosx14.0

I have not been able to reproduce the crash in apps built on my local Mac, but it seems to happen in apps uploaded to the app store.

wingsofdoug · 2024-12-03T20:40:12Z

I have just updated to:
MacOS: 15.1.1 (24B91)
Xcode: Version 16.1 (16B40)
swift --version produces: swift-driver version: 1.115 Apple Swift version 6.0.2 (swiftlang-6.0.2.1.2 clang-1600.0.26.4)
IOS-18.0 sims crash.
IOS-18.1 and 17.2 simulators do not crash

This is specifically when building for development.

For what its worth a coworker building the same application with these same versions does not cause the same crash.

Edit, This is for Rosetta Simulators.

HoonHaChoi · 2024-12-26T09:30:23Z

Hello, I've been struggling with the same problem recently.
Could you please let me know the iOS version where the problem occurred?

The problem only occurs in apps distributed through the App Store.

Issue iOS version is 18.0.0

Environment

xcode 16.1(16B40)
swift-driver version: 1.115 Apple Swift version 6.0.2 (swiftlang-6.0.2.1.2 clang-1600.0.26.4)
Target: arm64-apple-macosx15.0(24A335)

guidedways · 2024-12-26T09:43:08Z

@HoonHaChoi you should ask the users of your app to upgrade their iOS version to the latest. They're most likely (read: for sure) on one of the earlier beta versions with the issue. This is no longer an issue with 18 RC or above.

MarkVillacampa added bug A deviation from expected or documented behavior. Also: expected but undesirable behavior. crash Bug: A crash, i.e., an abnormal termination of software triage needed This issue needs more specific labels labels Aug 19, 2024

MarkVillacampa changed the title ~~withCheckedContinuation crashes on Xcode 16.1 beta 1~~ withCheckedContinuation crashes on Xcode 16 RC Sep 9, 2024

guidedways mentioned this issue Sep 17, 2024

Swift 6 withCheckedContinuation(isolation:) #75828

Open

andersio mentioned this issue Sep 18, 2024

VIT-7468: Workaround iOS 18 CheckedContinuation crash tryVital/vital-ios#244

Merged

kgaidis mentioned this issue Sep 19, 2024

Crash at launch Xcode 16 iOS 18 - EXC_BAD_ACCESS 0x100b63934 (0x100b638e0 + 84) specialized withCheckedContinuation<A>(isolation:function:_:) RevenueCat/purchases-ios#4177

Closed

12 tasks

jshier mentioned this issue Sep 21, 2024

EXC_BAD_ACCESS crash in withTaskCancellationHandler on Mac app designed for iPad and Xcode 16 Alamofire/Alamofire#3896

Open

1 task

kgaidis mentioned this issue Sep 25, 2024

[6.0.1] SILOptimizer: Allow inlining of transparent functions in @backDeployed thunks #76218

Merged

DougGregor closed this as completed Nov 8, 2024

crow mentioned this issue Dec 17, 2024

AirshipWorkManagers crash after upgrading to Xcode 16.1 urbanairship/ios-library#419

Closed

levochkaa mentioned this issue Jan 6, 2025

Fix/withCheckedContinuation crash apphud/ApphudSDK#127

Open

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withCheckedContinuation crashes on Xcode 16 RC #75952

withCheckedContinuation crashes on Xcode 16 RC #75952

MarkVillacampa commented Aug 19, 2024 •

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MarkVillacampa commented Aug 21, 2024

mszyszylo commented Sep 3, 2024 •

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MarkVillacampa commented Sep 9, 2024

random-yang commented Sep 10, 2024

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jshier commented Sep 21, 2024

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tshortli commented Sep 21, 2024 •

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abdorizak commented Oct 10, 2024

guidedways commented Oct 10, 2024

DougGregor commented Nov 8, 2024

DougGregor commented Nov 11, 2024

mike123789-dev commented Nov 15, 2024

tshortli commented Nov 15, 2024

mike123789-dev commented Nov 15, 2024

Lyine0924 commented Nov 20, 2024

wingsofdoug commented Dec 3, 2024 •

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HoonHaChoi commented Dec 26, 2024 •

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guidedways commented Dec 26, 2024

withCheckedContinuation crashes on Xcode 16 RC #75952

withCheckedContinuation crashes on Xcode 16 RC #75952

Comments

MarkVillacampa commented Aug 19, 2024 • edited Loading

Description

Reproduction

Stack dump

Expected behavior

Environment

Additional information

MarkVillacampa commented Aug 21, 2024

mszyszylo commented Sep 3, 2024 • edited Loading

MarkVillacampa commented Sep 9, 2024

random-yang commented Sep 10, 2024

kiran-nayak-cheq commented Sep 12, 2024

random-yang commented Sep 13, 2024

guidedways commented Sep 17, 2024 • edited Loading

jshier commented Sep 21, 2024

sergiocampama commented Sep 21, 2024

tshortli commented Sep 21, 2024 • edited Loading

abdorizak commented Oct 10, 2024

guidedways commented Oct 10, 2024

DougGregor commented Nov 8, 2024

DougGregor commented Nov 11, 2024

mike123789-dev commented Nov 15, 2024

tshortli commented Nov 15, 2024

mike123789-dev commented Nov 15, 2024

Lyine0924 commented Nov 20, 2024

Environment

wingsofdoug commented Dec 3, 2024 • edited Loading

HoonHaChoi commented Dec 26, 2024 • edited Loading

Environment

guidedways commented Dec 26, 2024

MarkVillacampa commented Aug 19, 2024 •

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mszyszylo commented Sep 3, 2024 •

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guidedways commented Sep 17, 2024 •

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tshortli commented Sep 21, 2024 •

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