SwiftUI: @State and sheets

Why doesn't this work? (Specifically, it crashes.)

struct Item: Identifiable, Hashable, Codable {
    var id = UUID()
    var name: String? = nil
}

private let defaults: [Item] = [
    Item(name: "Bread"),
    Item(),
    Item(name: "Peanut Butter"),
    Item(name: "Jelly")
]

struct ContentView: View {
    @State var selectedItem = Set<Item>()
    @State var showSheet = false
    
    var body: some View {
        VStack {
            ForEach(defaults, id: \.self) { item in
                Button(item.name ?? "<unnamed>") {
                    self.selectedItem.removeAll()
                    self.selectedItem.insert(item)
                    print("Selected item is now \(self.selectedItem)")
                    self.showSheet = true
                }
            }
        }
        .sheet(isPresented: self.$showSheet) {
            let _ = print("selected item \(self.selectedItem)")
            RenameSheet(name: self.selectedItem.first!.name ?? "<no name>") {
                self.selectedItem.removeAll()
            }
        }
        .padding()
    }
}

Based on the output from the prints, it gets set when the button is clicked, but is then empty when the sheet is presented.