I have a simple SwiftUI app with a sidebar and detail pane implement using NavigationSplitView. It works OK, except when (programmatically) deselecting the item selected in the list, the app crashes with an unhelpful stack trace (mostly ___lldb_unamed_symbol). Specifically, when selectedItem = nil, the app crashes.

The issue can be reproduced with the program below:

import SwiftUI

struct Person: Hashable {
    var firstName: String
    var lastName: String
}

struct PersonDetailView: View {

    var body: some View {
        if let selectedPersonBinding = Binding($selection) {
            VStack {
                TextField("First Name", text: selectedPersonBinding.firstName)
                TextField("Last Name", text: selectedPersonBinding.lastName)
            }
            .padding()
        }
    }

    @Binding var selection: Person?
}

struct ContentView: View {
    var body: some View {
        NavigationSplitView {
            List(people, id: .self, selection: $selectedPerson) {
                Text($0.firstName)
            }
            .toolbar {
                Button("Deselect") {
                    selectedPerson = nil
                }
            }
        } detail: {
            PersonDetailView(selection: $selectedPerson)
        }
        .onAppear() {
            selectedPerson = people[0]
        }
    }

    let people = [
        Person(firstName: "Steve", lastName: "Jobs"),
        Person(firstName: "Steve", lastName: "Wozniak"),
        Person(firstName: "Ronald", lastName: "Wayne")
    ]
    @State var selectedPerson: Person?
}

Run that on Mac or iPad, click the “Deselect” button, and the app will crash.

I’ve deduced that it has something to do with the detail view’s binding to selectedPerson, as the problem goes away if I remove that binding, but I can’t figure out why it should crash with that binding there.