iOS Swift: unsafeMutableAddressor crash on iOS 8

问题

With the stack trace, unsafeMutableAddressor crash seems to be when it access AppConstant.kShowOverlay from controller's viewDidLoad()

I have defined AppConstant.swift like below:

struct AppConstant {
    // MARK: Properties
    static let kShowOverlay = false
}

Following is the stack trace from crashlytics:

Crashed: com.apple.main-thread
    EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000048

    0  libswiftCore.dylib          0x51bfc5c _TTWuRq_Ss9Indexable_GVSs5Sliceq__Ss14CollectionTypeSsFS1_10suffixFromuRq_S1__fq_Fqq_S_5Indexqq_S1_11SubSequence
    1  MyAppModule                 0x56fbad4 AppConstants.kShowOverlay.unsafeMutableAddressor (AppConstants.swift)
    2  libdispatch.dylib           0x34ba9f13 dispatch_once_f + 62
    3  MyApp                       0x23e38e8 globalinit_33_D6508E60499748694DF7352631AEB836_func18 (MyViewController.swift:73)
    4  libdispatch.dylib           0x34ba92cf _dispatch_client_callout + 22
    5  libdispatch.dylib           0x34ba9f13 dispatch_once_f + 62
    6  MyApp                       0x2383e88 MyViewController.setupCollectionView(MyViewController) -> () -> () (MyViewController.swift:530)
    7  MyApp                       0x29f0a3c MyViewController.viewDidLoad(MyViewController) -> () -> () (MyViewController.swift:59)

I am not able to repro this crash, just have the stack trace from crashlytics.

Does anyone have any idea like, what could be the reason or how should I try to repro this crash?

Note: Crash only happens on iOS 8.

Any pointers would be greatly appreciated.

Update: My workspace has multiple projects, so the accessor file and the constant file that I am trying to access are in different project. Is there any possibility like project settings mismatch that can cause the crash?

来源：https://stackoverflow.com/questions/37732916/ios-swift-unsafemutableaddressor-crash-on-ios-8