Crash in MergeBasicSink with Xcode 11.2 #2099

akolov · 2019-11-01T09:15:43Z

Short description of the issue:

I'm getting crashes when using merge() with Xcode 11.2. Same code with 11.1 works fine.

What actually happens:

EXC_BAD_ACCESS (code=1, address=0x0)

    frame #0: 0x00007fff5132ba49 libswiftCore.dylib`_swift_initClassMetadataImpl(swift::TargetClassMetadata<swift::InProcess>*, swift::ClassLayoutFlags, unsigned long, swift::TypeLayout const* const*, unsigned long*, bool) + 1337
    frame #1: 0x0000000106c0bc46 Test`type metadata completion function for MergeSink at <compiler-generated>:0
    frame #2: 0x00007fff51332ced libswiftCore.dylib`swift::MetadataCacheEntryBase<(anonymous namespace)::GenericCacheEntry, void const*>::doInitialization(swift::ConcurrencyControl&, swift::MetadataCompletionQueueEntry*, swift::MetadataRequest) + 285
    frame #3: 0x00007fff51329767 libswiftCore.dylib`swift_getGenericMetadata + 1527
    frame #4: 0x0000000106c0bc90 Test`type metadata accessor for MergeSink at <compiler-generated>:0
    frame #5: 0x00007fff513420e1 libswiftCore.dylib`(anonymous namespace)::DecodedMetadataBuilder::createBoundGenericType(swift::TargetContextDescriptor<swift::InProcess> const*, llvm::ArrayRef<swift::TargetMetadata<swift::InProcess> const*>, swift::TargetMetadata<swift::InProcess> const*) const + 257
    frame #6: 0x00007fff51340e7e libswiftCore.dylib`swift::Demangle::TypeDecoder<(anonymous namespace)::DecodedMetadataBuilder>::decodeMangledType(swift::Demangle::Node*) + 3726
    frame #7: 0x00007fff5133e32b libswiftCore.dylib`swift_getTypeByMangledNodeImpl(swift::MetadataRequest, swift::Demangle::Demangler&, swift::Demangle::Node*, void const* const*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 411
    frame #8: 0x00007fff5133e132 libswiftCore.dylib`swift::swift_getTypeByMangledNode(swift::MetadataRequest, swift::Demangle::Demangler&, swift::Demangle::Node*, void const* const*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 482
    frame #9: 0x00007fff5133e6bb libswiftCore.dylib`swift_getTypeByMangledNameImpl(swift::MetadataRequest, llvm::StringRef, void const* const*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 779
    frame #10: 0x00007fff5133c1c2 libswiftCore.dylib`swift::swift_getTypeByMangledName(swift::MetadataRequest, llvm::StringRef, void const* const*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 482
    frame #11: 0x00007fff51330d7a libswiftCore.dylib`getSuperclassMetadata(swift::TargetClassMetadata<swift::InProcess>*, bool) + 330
    frame #12: 0x00007fff5132b53b libswiftCore.dylib`_swift_initClassMetadataImpl(swift::TargetClassMetadata<swift::InProcess>*, swift::ClassLayoutFlags, unsigned long, swift::TypeLayout const* const*, unsigned long*, bool) + 43
    frame #13: 0x0000000106c0b905 Test`type metadata completion function for MergeBasicSink at <compiler-generated>:0
    frame #14: 0x00007fff51332ced libswiftCore.dylib`swift::MetadataCacheEntryBase<(anonymous namespace)::GenericCacheEntry, void const*>::doInitialization(swift::ConcurrencyControl&, swift::MetadataCompletionQueueEntry*, swift::MetadataRequest) + 285
    frame #15: 0x00007fff51329767 libswiftCore.dylib`swift_getGenericMetadata + 1527
    frame #16: 0x0000000106c0b4b0 Test`type metadata accessor for MergeBasicSink at <compiler-generated>:0
  * frame #17: 0x0000000106c09e24 Test`Merge.run<SourceSequence>(observer=0x0000600002b249c0, cancel=0x0000600002421260, self=0x0000600000f3cea0) at Merge.swift:580:20
    frame #18: 0x0000000106c2e535 Test`Producer.subscribe<Element>(observer=0x0000600002b249c0, self=0x0000600000f3cea0) at Producer.swift:18:44
    frame #19: 0x0000000106bfa690 Test`Map.run<SourceType>(observer=0x000060000017a640, cancel=0x0000600002420f50, self=0x000060000017a4f0) at Map.swift:99:41
    frame #20: 0x0000000106c2ee28 Test`closure #1 in Producer.subscribe<Element>(_0=() @ scalar, self=0x000060000017a4f0, observer=0x000060000017a640) at Producer.swift:26:48
    frame #21: 0x0000000106c2ef3c Test`partial apply for closure #1 in Producer.subscribe<A>(_:) at <compiler-generated>:0
    frame #22: 0x0000000106bcc1cc Test`thunk for @escaping @callee_guaranteed () -> (@out Disposable) at <compiler-generated>:0
    frame #23: 0x0000000106c2ef91 Test`partial apply for thunk for @escaping @callee_guaranteed () -> (@out Disposable) at <compiler-generated>:0
    frame #24: 0x0000000106bb875f Test`CurrentThreadScheduler.schedule<StateType>(state=() @ 0xffffffffffffffff, action=0x0000000106c2ef80 Test`partial apply forwarder for reabstraction thunk helper from @escaping @callee_guaranteed () -> (@out RxSwift.Disposable) to @escaping @callee_guaranteed (@in_guaranteed ()) -> (@out RxSwift.Disposable) at <compiler-generated>, self=0x0000600000d282b0) at CurrentThreadScheduler.swift:101:30
    frame #25: 0x0000000106c2e714 Test`Producer.subscribe<Element>(observer=0x000060000017a640, self=0x000060000017a4f0) at Producer.swift:24:52
    frame #26: 0x0000000106c1633d Test`ObservableType.subscribe(on=0x0000000106d122b0 Test`partial apply forwarder for closure #1 (RxSwift.Event<A.Element>) -> () in (extension in RxCocoa):RxSwift.ObservableType.(bind in _F14B11F29E4023218E8359F9EC4A42AD)<A where A1: RxSwift.ObserverType, A.Element == A1.Element>(to: Swift.Array<A1>) -> RxSwift.Disposable at <compiler-generated>, self=0x000060000017a4f0) at ObservableType+Extensions.swift:25:40
    frame #27: 0x0000000106d11983 Test`ObservableType.bind<Self>(observers=1 value, self=0x000060000017a4f0) at Observable+Bind.swift:42:21
    frame #28: 0x0000000106d118bd Test`ObservableType.bind<Self>(observers=1 value, self=0x000060000017a4f0) at Observable+Bind.swift:20:21
    frame #29: 0x0000000106b3dafc Test`AppDelegate.application(application=0x00007fcb08c00080, launchOptions=nil, self=0x0000600000d08150) at AppDelegate.swift:27:6
    frame #30: 0x0000000106b3e4b4 Test`@objc AppDelegate.application(_:didFinishLaunchingWithOptions:) at <compiler-generated>:0
    frame #31: 0x00007fff478467a8 UIKitCore`-[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:] + 232
    frame #32: 0x00007fff478481b7 UIKitCore`-[UIApplication _callInitializationDelegatesWithActions:forCanvas:payload:fromOriginatingProcess:] + 3980
    frame #33: 0x00007fff4784dd06 UIKitCore`-[UIApplication _runWithMainScene:transitionContext:completion:] + 1281
    frame #34: 0x00007fff46f84422 UIKitCore`-[_UISceneLifecycleMultiplexer completeApplicationLaunchWithFBSScene:transitionContext:] + 179
    frame #35: 0x00007fff4784a2a6 UIKitCore`-[UIApplication _compellApplicationLaunchToCompleteUnconditionally] + 59
    frame #36: 0x00007fff4784a5a5 UIKitCore`-[UIApplication _run] + 754
    frame #37: 0x00007fff4784fb68 UIKitCore`UIApplicationMain + 1621
    frame #38: 0x0000000106b3eaeb Test`main at AppDelegate.swift:14:7
    frame #39: 0x00007fff51a1dc25 libdyld.dylib`start + 1
    frame #40: 0x00007fff51a1dc25 libdyld.dylib`start + 1

Self contained code example that reproduces the issue:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    let aBinder = Binder<String>(self) { _, str in
      print(str)
    }

    _ = Observable.of(
      NotificationCenter.default.rx.notification(UIApplication.willResignActiveNotification),
      NotificationCenter.default.rx.notification(UIApplication.didBecomeActiveNotification)
    )
    .merge()
    .map { _ in "test" }
    .bind(to: aBinder)

    return true
}

Sample project is attached: Test.zip

RxSwift/RxCocoa/RxBlocking/RxTest version/commit

5.0.1

Platform/Environment

How easy is to reproduce? (chances of successful reproduce after running the self contained code)

easy, 100% repro
sometimes, 10%-100%
hard, 2% - 10%
extremely hard, %0 - 2%

Xcode version:

Version 11.2 (11B52)

Installation method:

SPM
CocoaPods
Carthage
Git submodules

I have multiple versions of Xcode installed:
(so we can know if this is a potential cause of your issue)

yes (which ones)
no

Level of RxSwift knowledge:
(this is so we can understand your level of knowledge
and formulate the response in an appropriate manner)

just starting
I have a small code base
I have a significant code base

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

achernoprudov · 2019-11-01T12:46:23Z

Related to #2094

tcldr · 2019-11-01T13:07:27Z

As mentioned in other issue thread – caused by SR-11564. (https://bugs.swift.org/browse/SR-11564)

freak4pc · 2019-11-01T15:35:48Z

🤦‍♂

kzaher · 2019-11-01T21:38:02Z

Usually when somebody says

Xcode 11.2. Same code with 11.1 works fine.

that means it's not our bug :)

RamblinWreck77 · 2019-11-01T23:00:29Z

Temporary workaround that fixes it:

-Go to Project Target/Build Settings
-"Dead Code Stripping" to NO

akolov · 2019-11-02T03:20:50Z

Confirming that setting Dead Code Stripping to NO works. Otherwise crashes happen even when compiled with Xcode 11.1 after submitting to TestFlight.

sree127 · 2019-11-04T15:27:59Z

I'm not able to run XCTests on Xcode 11.1,11.2 as it crashes from debounce with Thread 1: EXC_BAD_ACCESS (code=1, address=0x0)

Dead Code Stripping is set to NO
Anyone else experiencing the same issue or any work around for this case? (It works in Xcode 10.3)

brooksdubois · 2019-12-11T10:11:02Z

Seeing this issue with a very simple code sample built using Carthage

Dead Code Stripping set to No

var updateString = BehaviorRelay<String>(value: "")

@IBOutlet weak var fetchButton: UIButton!
@IBOutlet weak var outputLabel: UILabel!

@IBAction func buttonTapped(_ sender: UIButton) {
  updateString.accept("Updated")
}
override func viewDidLoad() {
  super.viewDidLoad()
  updateString.bind(to: outputLabel.rx.text).disposed(by: disposeBag)
}

Crashes me immediately while initializing the Binder

freak4pc · 2020-01-05T18:49:40Z

Unfortunately this is a bug with SPM. People already filed a bug and I hope it would be fixed soon, but there's nothing much we can do as a framework.

pauljohanneskraft mentioned this issue Nov 7, 2019

EXC_BAD_ACCESS on Release build QuickBirdEng/XCoordinator#144

Closed

willsr mentioned this issue Nov 21, 2019

Crash in release build configuration when using Swift Package Manager Moya/Moya#1958

Open

titiphoque mentioned this issue Dec 3, 2019

Crash with Xcode 11.2.1 DEBUG build configuration CombineCommunity/CombineDataSources#2

Open

freak4pc closed this as completed Jan 5, 2020

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Crash in MergeBasicSink with Xcode 11.2 #2099

Crash in MergeBasicSink with Xcode 11.2 #2099

akolov commented Nov 1, 2019 •

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achernoprudov commented Nov 1, 2019

tcldr commented Nov 1, 2019

freak4pc commented Nov 1, 2019

kzaher commented Nov 1, 2019

RamblinWreck77 commented Nov 1, 2019 •

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akolov commented Nov 2, 2019 •

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sree127 commented Nov 4, 2019

brooksdubois commented Dec 11, 2019

freak4pc commented Jan 5, 2020

Crash in MergeBasicSink with Xcode 11.2 #2099

Crash in MergeBasicSink with Xcode 11.2 #2099

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akolov commented Nov 1, 2019 • edited Loading

achernoprudov commented Nov 1, 2019

tcldr commented Nov 1, 2019

freak4pc commented Nov 1, 2019

kzaher commented Nov 1, 2019

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sree127 commented Nov 4, 2019

brooksdubois commented Dec 11, 2019

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akolov commented Nov 1, 2019 •

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akolov commented Nov 2, 2019 •

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