Thread 1: EXC_BREAKPOINT (code=1, subcode=0x1af84999c)

I am trying to create a Multiplatform Document Based app using SwiftUI.

I have a List which the user can reorder by dragging Items using .onMove. It works fine in macOS but crashes iOS every time with the above message alongside @main

The relevant code is-

struct ContentView: View {
…

List {
					ForEach(Array(document.journey.items.enumerated()), id: \.1.id) { (index, item) in
						Section {
							HStack {
								Text("\(index+1)")
									…
								Text("\(item.address)"
								…							
}  // End HStack
							.background(
			
								Capsule()
									.fill((selection.contains(item.id) ? Color.red : Color.blue))
									.onTapGesture(perform: {
										
										if selection.contains(item.id) {
											selection.remove(item.id)
											
										} else {
											selection.insert(item.id)
										}
									})
							)
							.font(.headline)
							.foregroundColor(.white)
						
						} // End Section
			…
					}  // End ForEach
					.onDelete(perform: delete)
					.onMove { offsets, toOffset in
						document.moveItems(offsets: offsets, toOffset: toOffset, undoManager: undoManager)
					}
						} // End List
////////
final class MultiStopDocument: ReferenceFileDocument {
…

func moveItems(offsets: IndexSet, toOffset: Int, undoManager: UndoManager? = nil) {
        let oldItems = journey.items

// BREAK POINT

        print("GOT to First")
        withAnimation {
            journey.items.move(fromOffsets: offsets, toOffset: toOffset)
        }
        print("GOT to Second")
        
#if os(macOS)
        undoManager?.registerUndo(withTarget: self) { doc in
            
            doc.replaceItems(with: oldItems, undoManager: undoManager)
        }
#endif
    }
///////////
import SwiftUI

@main  - Thread 1: EXC_BREAKPOINT (code=1, subcode=0x1af84999c)
struct MultiStopApp: App {

Console macOS stepping :-

GOT to First GOT to Second

Console iOS stepping :-

2023-06-07 12:03:16.869439+0100 MultiStop[27341:6172177] -[UITextEffectsWindow _accessibilityFindSubviewDescendant:]: unrecognized selector sent to instance 0x112037400 GOT to First 2023-06-07 12:03:52.083774+0100 MultiStop[27341:6172433] XPC connection interrupted GOT to Second THEN CRASH

Answered by FrancisW in 755425022

Update-

I managed to get a lab appointment with WWDC. Thanks very much to the Apple people who helped me. It took a large part of the 30 minute appointment but they found a solution.

Further to the code that I posted above the List was enclosed in a Section (you can see where I commented // End Section above). Removing the Section made everything work.

I still don't know why it worked on macOS but at the moment I am just happy that it is working on iOS as well.

Thanks for taking the time to look, those of you that did, and maybe I could be a pointer for others who keep searching like I had been.

Accepted Answer

Update-

I managed to get a lab appointment with WWDC. Thanks very much to the Apple people who helped me. It took a large part of the 30 minute appointment but they found a solution.

Further to the code that I posted above the List was enclosed in a Section (you can see where I commented // End Section above). Removing the Section made everything work.

I still don't know why it worked on macOS but at the moment I am just happy that it is working on iOS as well.

Thanks for taking the time to look, those of you that did, and maybe I could be a pointer for others who keep searching like I had been.

could you explain the cause of the problem in detail, i have the same question @FrancisW

Thread 1: EXC_BREAKPOINT (code=1, subcode=0x1af84999c)
 
 
Q