ios - 尝试存档时自定义 NavigationStack 导致 `error: Segmentation fault: 11` 时的解决方法建议？

Question

我目前正在使用自定义 NavigationStack 来控制我的导航，如 this article 中所建议的那样.

我能够成功运行构建、模拟、测试和分析，但是在运行存档时，Xcode 在完成之前抛出错误:Segmentation fault: 11。

我已经通过反复试验将导致此错误的代码精确定位到 advance(_:) 方法(在 NavigationStack.swift 中)中的某个位置。

    func advance<V: View & Navigatable>(_ view: V) {
        let item = NavigationItem(view)
        viewStack.append( currentView )
        withAnimation {
            self.navigate = .forward
        }
        //>>>>>>>> HERE'S THE PROBLEM <<<<<<<<<
        // ↓this↓ causes the Archive to fail.
        currentView = item
    }

我的环境:macOS Catalina - 版本 10.15.2，Xcode - 版本 11.3 (11C29)。(但是，我在从 macOSCatalina10.15.1 和 Xcode11.2 更新之前遇到了这个问题)

如果有帮助，我的其他源码如下:

SceneDelegate.swift:

class SceneDelegate: UIResponder, UIWindowSceneDelegate {
...
    let contentView = ContentView()//.environmentObject(UserData())
...
}

ContentView.swift:

struct ContentView: View {
    //@EnvironmentObject var userData: UserData   
    var body: some View {
        NavigationHost()
            //.environmentObject(NavigationStack( --Commented out in Edit
            //    NavigationItem(view: AnyView( HomeView() ) --Commented out in Edit
            .environmentObject(NavigationStack( HomeView() ))
                    .transition(.move(edge: .trailing))
            //.environmentObject(userData)
    }
}

NavigationHost.swift:

struct NavigationHost: View{
    @EnvironmentObject var navigation: NavigationStack
    //@EnvironmentObject var userData: UserData

    var body: some View {
            ZStack {
                   if self.navigation.navigate == .root {
                    self.navigation.currentView.view
                    //.environmentObject(self.userData)
                    .environmentObject(self.navigation)
                }
                else if self.navigation.navigate == .backward {
                    self.navigation.currentView.view
                    //.environmentObject(self.userData)
                    .environmentObject(self.navigation)
                        .transition(.move(edge: .leading))
                }
                if self.navigation.navigate == .forward {
                    self.navigation.currentView.view
                    //.environmentObject(self.userData)
                    .environmentObject(self.navigation)
                        .transition(.move(edge: .trailing))
                } 
                   ...
          }
    }
}

NavigationStack.swift:

final class NavigationStack: ObservableObject {
    enum Direction {
        case root
        case forward
        case backward
    }

    @Published var viewStack: [NavigationItem] = []
    @Published var currentView: NavigationItem
    @Published var navigate: Direction = .root
    @Published var turnOnCloseButton: Bool = false
    @Published var turnOnBackButton: Bool = false

    init<V: View & Navigatable>(_ view: V, description: String? = nil) {
        let currentView = NavigationItem(view, description: description)
        print("Navigation Stack Initialized")
        self.currentView = currentView
    }


    func back(turnOffBack: Bool = true, turnOffClose: Bool = true) {
        if turnOffBack { turnOnBackButton = false }
        if turnOffClose { turnOnCloseButton = false }
        if viewStack.count == 0 {
            return
        }
        let last = viewStack.count - 1
        currentView = viewStack[last]
        withAnimation {
            self.navigate = .backward
        }
        viewStack.remove(at: last)
    }

    func advance<V: View & Navigatable>(_ view: V) {
        let item = NavigationItem(view)
        viewStack.append( currentView )
        withAnimation {
            self.navigate = .forward
        }
        //>>>>>>>> HERE'S THE PROBLEM <<<<<<<<<
        // ↓this↓ causes the Archive to fail.
        currentView = item
    }

    func home() {
        currentView = NavigationItem( HomeeView() )
        viewStack.removeAll()
        withAnimation {
            self.navigate = .root
        }
    }

    func bringToFront<V: View & Navigatable>(_ view: V) {
        let item = NavigationItem(view)
        viewStack = viewStack.filter { $0 != item }
        //advance(view)
    }

}

struct NavigationItem: Equatable{
    var view: AnyView
    let id: String = UUID().uuidString
    var description: String

    init< V: View & Navigatable >(_ view: V, description: String? = nil) {
        self.view = AnyView(view)
        if description==nil {
            self.description = V.getDescription(view)()//"\(type(of: view))"
        } else {
            self.description = description!
        }
    }

    static func == (lhs: NavigationItem, rhs: NavigationItem) -> Bool {
        return lhs.description == rhs.description
    }
}

protocol Navigatable {
    var description: String { get }
}

extension Navigatable {
    func getDescription() -> String {
        return "\(type(of: self))"
    }
}

我之前也问过关于 NavigationStack 的问题，但是 different issue .

我在 2 周前通过反馈助手发送了一份错误报告，但还没有得到任何结果。

我急于部署 TestFlight，非常感谢任何帮助!

编辑:这是存档失败的错误消息的一部分:

...
1.  While running pass #41789 SILFunctionTransform "GenericSpecializer" on SILFunction "@$s8okan_app15NavigationStackC7advanceyyx7SwiftUI4ViewRzAA11NavigatableRzlFAA04NextH0V_Tg5".
 for 'advance(_:)' (at /Users/myname/Downloads/my-project/my-project/Navigations/NavigationStack.swift:48:2)
0  swift                    0x0000000112c88a63 PrintStackTraceSignalHandler(void*) + 51
1  swift                    0x0000000112c88236 SignalHandler(int) + 358
2  libsystem_platform.dylib 0x00007fff6627942d _sigtramp + 29
3  libsystem_platform.dylib 0x0000000800000001 _sigtramp + 2581097457
4  swift                    0x000000010f0cd08c swift::ReabstractionInfo::prepareAndCheck(swift::ApplySite, swift::SILFunction*, swift::SubstitutionMap, swift::OptRemark::Emitter*) + 572
5  swift                    0x000000010f11fc5a swift::ReabstractionInfo::ReabstractionInfo(swift::ApplySite, swift::SILFunction*, swift::SubstitutionMap, swift::IsSerialized_t, bool, swift::OptRemark::Emitter*) + 122
6  swift                    0x000000010f129cb5 swift::trySpecializeApplyOfGeneric(swift::SILOptFunctionBuilder&, swift::ApplySite, llvm::SmallSetVector<swift::SILInstruction*, 8u>&, llvm::SmallVectorImpl<swift::SILFunction*>&, swift::OptRemark::Emitter&) + 1653
7  swift                    0x000000010f0027b1 (anonymous namespace)::GenericSpecializer::run() + 2673
8  swift                    0x000000010ef7bfbe swift::SILPassManager::execute() + 4606
9  swift                    0x000000010ebda9eb swift::CompilerInstance::performSILProcessing(swift::SILModule*, swift::UnifiedStatsReporter*) + 6379
10 swift                    0x000000010e8d2f45 performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*, swift::UnifiedStatsReporter*) + 33925
11 swift                    0x000000010e8c72b4 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 6820
12 swift                    0x000000010e8547b3 main + 1219
13 libdyld.dylib            0x00007fff660807fd start + 1
14 libdyld.dylib            0x00000000000000d2 start + 2583165142
error: Segmentation fault: 11 (in target 'my-project' from project 'my-project')

Answer 1

要么你错过了一些代码，要么有一些错误:

NavigationStack 必须按如下方式调用:

var body: some View {
    NavigationHost()
        .environmentObject(NavigationStack(
            HomeView() ))

        //.environmentObject(userData)
}