A simple test app for demonstrating view update warnings occurring in iOS 16

ContentView.swift

import SwiftUI

struct ContentView: View {
    var body: some View {
        RootView()
            .modifier(RootViewModifier())
    }
}


enum RootTab: String {
    case profile, mentions, timeline
    
    var title: String {
        rawValue.capitalized
    }
}

struct RootView: View {
    
    @EnvironmentObject private var interface: InterfaceStore
    
    var body: some View {
        TabView {
            ForEach(interface.tabs, id: \.hashValue) { tab in
                NavigationStack {
                    Text(tab.title)
                        .navigationTitle(tab.title)
                        .toolbar {
                            Button("Settings") {
                                interface.presentedSheet = .settings
                            }
                        }
                }
                .tabItem {
                    Text(tab.rawValue.capitalized)
                }
            }
        }
    }
}


struct RootViewModifier: ViewModifier {
    
    @StateObject private var interface = InterfaceStore()
    @StateObject private var user = UserStore()
    
    func body(content: Content) -> some View {
        content
            .sheet(item: $interface.presentedSheet) { sheet in
                switch sheet {
                case .settings:
                    SettingsView()
                }
            }
            .environmentObject(interface)
            .environmentObject(user)
    }
}


enum PresentedSheet: String, Identifiable {
    case settings
    
    var id: String {
        rawValue
    }
}

final class InterfaceStore: ObservableObject {
    @Published var tabs = [RootTab.timeline, .mentions, .profile]
    @Published var presentedSheet: PresentedSheet?
}


struct SettingsView: View {
    
    @Environment(\.dismiss) private var dismiss
    
    @EnvironmentObject private var user: UserStore
    
    @State private var isShowingAuthentication = false
    
    var body: some View {
        NavigationStack {
            List {
                Section {
                    usersSection(user.users.sorted { $0.value > $1.value })
                    
                    Button("Add Account") {
                        isShowingAuthentication = true
                    }
                }
            }
            .navigationTitle("Settings")
            .sheet(isPresented: $isShowingAuthentication) {
                NavigationStack {
                    Form {
                        TextField("Username", text: .constant(""))
                        SecureField("Password", text: .constant(""))
                    }
                    .navigationTitle("Sign In")
                }
            }
            .toolbar {
                ToolbarItem(placement: .confirmationAction) {
                    Button {
                        dismiss()
                    } label: {
                        Text("Done")
                    }

                }
            }
        }
    }
    
    func usersSection(_ users: [(UUID, String)]) -> some View {
        ForEach(users, id: \.0) { id, username in
            Button {
                user.activeUserID = id // FIXME: selecting row causes view update warnings here
            } label: {
                Label(username, systemImage: user.activeUserID == id ? "checkmark.circle" : "circle")
            }
        }
        .onDelete { indices in
            for i in indices {
                user.users.removeValue(forKey: users[i].0)
            }
        }
    }
}


final class UserStore: ObservableObject {
    
    @Published var activeUserID: UUID?
    @Published var users: [UUID: String]
    
    init() {
        let activeID = UUID()
        self._activeUserID = .init(initialValue: activeID)
        self._users = .init(initialValue: [activeID: "billy", UUID(): "bobby"])
    }
}


struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        RootView()
            .modifier(RootViewModifier())
    }
}

PublishedWarningsApp.swift

import SwiftUI

// Minimum Deployment Target: 16.0
// Built with Xcode 14.1 beta 3 (14B5033e)

@main // FIXME: dismissing SettingsView causes view update warnings here
struct PublishedWarningsApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}