Possible crash ...

[smhk]

7.5.0 recently upgraded to Xcode Version 16.4 (16F6)

I happened to run it on an 18.0 simulator (iPhone 16 fwiw) and:

No crash on 18.5 or others I checked.

With the same project, I have never once seen a crash when using current iOS (sim or device) and current Xcode, for the last 6 or so months

Of course, it could relate to my own code in some way, but seems unlikely

FYI !!

it takes ages to tease these things out, that's all I have so far.

[groue]

Hi @smhk,

Thanks for the report! Were you able to capture a complete crash report, full stack trace, something as exhaustive as possible as you can get?

[smhk]

@groue not yet! I will try my best ASAP. I was extremely pressed for time and wanted to rush in a report ...

The recent Xcode have some weird problems like this I spotted

Reports coming soon!

[smhk]

@groue thanks!

report.txt

and the bt

(lldb) bt
* thread #6, queue = 'com.apple.root.user-initiated-qos.cooperative', stop reason = EXC_BAD_ACCESS (code=1, address=0x4)
  * frame #1: 0x0000000104e3d09c PS Project, general.debug.dylib`Mutex<A>.withCancellableContinuation<A>(fn=0x0000000104e3d4c4 PS Project, general.debug.dylib`partial apply forwarder for closure #1 (Swift.UnsafeContinuation<A, Swift.Error>) -> () in GRDB.SerializedDatabase.execute<A where A: Swift.Sendable>(@Sendable (GRDB.Database) throws -> A) async throws -> A at <compiler-generated>) at SerializedDatabase.swift:363:19
    frame #2: 0x0000000104e3c740 PS Project, general.debug.dylib`SerializedDatabase.execute<()>(block=0x0000000104e0657c PS Project, general.debug.dylib`partial apply forwarder for closure #1 @Sendable (GRDB.Database) throws -> A1 in GRDB.DatabaseWriter.write<A where A1: Swift.Sendable>(@Sendable (GRDB.Database) throws -> A1) async throws -> A1 at <compiler-generated>) at SerializedDatabase.swift:251:35
    frame #3: 0x0000000104de0740 PS Project, general.debug.dylib`DatabaseQueue.writeWithoutTransaction<()>(updates=0x0000000104e0657c PS Project, general.debug.dylib`partial apply forwarder for closure #1 @Sendable (GRDB.Database) throws -> A1 in GRDB.DatabaseWriter.write<A where A1: Swift.Sendable>(@Sendable (GRDB.Database) throws -> A1) async throws -> A1 at <compiler-generated>) at DatabaseQueue.swift:390:26
    frame #5: 0x0000000104e06170 PS Project, general.debug.dylib`DatabaseWriter.write<GRDB.DatabaseQueue>(updates=0x0000000104a459c8 PS Project, general.debug.dylib`partial apply forwarder for closure #1 @Sendable (GRDB.Database) throws -> () in PS_Project__general.DB.sync(fieldCode: Swift.String) async -> () at <compiler-generated>) at DatabaseWriter.swift:645:19
    frame #6: 0x0000000104a44580 PS Project, general.debug.dylib`DB.sync(fieldCode="Odessa") at DB+sync.swift:30:35
    frame #7: 0x0000000104af8e38 PS Project, general.debug.dylib`LoaderService._when_launch() at LoaderService.swift:100:22
    frame #8: 0x0000000104af85b0 PS Project, general.debug.dylib`closure #1 in LoaderService.when_launch() at LoaderService.swift:81:27
    frame #10: 0x0000000104af78b8 PS Project, general.debug.dylib`closure #1 in TaskQueue.dispatch(oldTask=Swift.Task<Swift.Void, Swift.Never> @ 0x00000001101170b8, block=0x00000001052b0398 async function pointer to partial apply forwarder for closure #1 () async -> () in PS_Project__general.LoaderService.when_launch() -> ()) at LoaderService.swift:29:19

[smhk]

@groue I checked and it ONLY happens with simulator 18.0. I tried every other 18.x and there is no crash. This on Xcode 16.4 (16F6).

Unfortunately we don't have an 18.0 device left on hand

I will try to hunt down precisely where the issue happens in my upstream code.

Everything is run in a task queue which is the reference you see in LoaderService.swift

///Perfect simple task queue.
///WTT RickyMo stackoverflow.com/q/71586634/294884
fileprivate class TaskQueue {
    private var currentTask : Task<Void,Never> = Task{}
    
    ///Send in an an await function()
    ///- Example,
    ///- `.dispatch { await thing() }`
    ///- where
    ///- `func thing() async { await blah() }`
    func dispatch(block: @escaping () async -> Void) {
        let oldTask = currentTask
        currentTask = Task{
            _ = await oldTask.value
            await block()
        }
    }
}

[groue]

Cool. The stack trace is not very informative. Now since you can reproduce the crash, it would be very appreciated if you would share a reproducing sample code or project.

[smhk]

reproducing sample code or project

Thanks. I will definitely try to do that. It might take me a couple days to get to it.

normally I'd be happy to just privately send the whole project over but it's a secure project unfortunately.

It's an enormous project so it will take me a while to discombobulate a test case, will do ..