In iOS 18, we encountered a crash: Thread 4 name: com.apple.root.user-interactive-qos Thread 4 Crashed: 0 CoreFoundation 0x18c4f9b10 __CFCheckCFInfoPACSignature + 4 1 CoreFoundation 0x18c53ed64 CFBundleGetInfoDictionary + 24 2 CoreFoundation 0x18c53ed1c CFBundleGetIdentifier + 16 3 Foundation 0x18b153740 -[NSUserDefaults(NSUserDefaults) _initWithSuiteName:container:] + 84 4 UIKitCore 0x18ef26ef0 ___UIKitUserDefaults_block_invoke + 40 5 libdispatch.dylib 0x1941ee0d0 _dispatch_client_callout + 20 6 libdispatch.dylib 0x1941ef918 _dispatch_once_callout + 32 7 UIKitCore 0x18ef9de28 _UIKitUserDefaults + 80 8 UIKitCore 0x18f058a7c ___UIKitPreferencesOnce_block_invoke + 20 9 libdispatch.dylib 0x1941ee0d0 _dispatch_client_callout + 20 10 libdispatch.dylib 0x1941ef918 _dispatch_once_callout + 32 11 UIKitCore 0x18f056c8c _UIKitPreferencesOnce + 80 12 UIKitCore 0x18f0563b8 ___UIApplicationMainPreparations_block_invoke + 20 13 libdispatch.dylib 0x1941ec370 _dispatch_call_block_and_release + 32 14 libdispatch.dylib 0x1941ee0d0 _dispatch_client_callout + 20 15 libdispatch.dylib 0x1941fff60 _dispatch_root_queue_drain + 860 16 libdispatch.dylib 0x194200590 _dispatch_worker_thread2 + 156 17 libsystem_pthread.dylib 0x2136ffc40 _pthread_wqthread + 228 18 libsystem_pthread.dylib 0x2136fc488 start_wqthread + 8 Below image show more details: And after set a symbol breakpoint: [NSUserDefaults _initWithSuiteName:container:] We found that at the beginning of app launch, the system will call it: It not always crash, but sometimes especially when app upgrade, what the root cause maybe?

When use Xcode15 and iOS 14 simulator to run app, it will crash, and the crash stack is: Thread 1 Queue : com.apple.main-thread (serial) #0 0x0000000104b074a5 in __cxx_global_var_init.4 () #1 0x000000014fb6ec95 in ImageLoaderMachO::doModInitFunctions(ImageLoader::LinkContext const&) () #2 0x000000014fb6f08a in ImageLoaderMachO::doInitialization(ImageLoader::LinkContext const&) () #3 0x000000014fb69bb7 in ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) () #4 0x000000014fb67ec7 in ImageLoader::processInitializers(ImageLoader::LinkContext const&, unsigned int, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) () #5 0x000000014fb67f68 in ImageLoader::runInitializers(ImageLoader::LinkContext const&, ImageLoader::InitializerTimingList&) () #6 0x000000014fb5b26b in dyld::initializeMainExecutable() () #7 0x000000014fb5ff56 in dyld::_main(macho_header const*, unsigned long, int, char const**, char const**, char const**, unsigned long*) () #8 0x000000014fb5a1c2 in start_sim () #9 0x000000024760e424 in dyld4::prepareSim(dyld4::RuntimeState&, char const*) () #10 0x000000024760cabc in dyld4::prepare(dyld4::APIs&, dyld3::MachOAnalyzer const*) () #11 0x000000024760c3bd in start () And I found two same issues: 1.https://issuetracker.google.com/issues/301372178; 2.https://github.com/realm/realm-swift/issues/8369 From these two issue, I know Xcode15 use new linker(ld_prime), and not support iOS <15; So if we want to support iOS 14, we only have one solution that add the -Wl,-ld_classic options to the OTHER_LDFLAGS? And for now, the crash only happened in iOS 14 simulator, but will it affect the iPhone device if we don't add the -Wl,-ld_classic options to the OTHER_LDFLAGS?

I have a app that need to use libbz, and when use Xcode to build and launch, it will crash and the console will print: dyld log And I found when I set the compiler settings for debug: Optimization Level -> Fastest, smallest[-Os] Link Time Optimization -> No the crash does not appear. but for debug, I think the the right compiler settings is: Optimization Level -> None[-O0] Link Time Optimization -> Increment why this happened and what can I do to fix it?

When debug app, it will crash when app launch, and print below info: libbz2.1.0.dylib is a system library, and how we can resolve this problem?

in iOS16, there are A viewController, and when push to a new ViewController, and the new ViewController sets it's navigationItem.titleView to a UISearchBar, and then pop back to A viewController, the UINavigarionBar's height is incorrect. is there any methods I can recover the UINavigarionBar's height?