title: Crash when delete a record from coredata in SwiftUI
body: <p>I make a list for audio items from coredata. after deleting, crash reported as "EXC_BREAKPOINT (code=1, subcode=0x1b8fb693c)", why?</p>
  
  <p>When using </p>
  
  <pre><code>ForEach(items, id: \.self)
  </code></pre>
  
  <p>, it works. But My Audio has id property and follow Identifiable protocol.</p>
  
  <p>UPDATE: I found adding a if{} clause will fix crash, but why? Breakpoint at "static UUID.<em>unconditionallyBridgeFromObjectiveC(</em>:) ()".</p>
  
  <pre><code>struct Test1View: View {
      @Environment(\.managedObjectContext) var context
      @FetchRequest(fetchRequest: Audio.fetchAllAudios()) var items: FetchedResults&lt;Audio&gt;
      var body: some View {
          List {
              ForEach(items) { item in
                  if true { // &lt;- this if clause fix crash, but why?
                      HStack {
                          Text("\(item.name)")
                      }
                  }
              }.onDelete(perform: { indexSet in
                  let index = indexSet.first!
                  let item = self.items[index]
                  self.context.delete(item)
                  try? self.context.save()
              })
          }
      }
  }
  </code></pre>
  
  <p>code as following:</p>
  
  <pre><code>class Audio: NSManagedObject, Identifiable {
      @NSManaged public var id: UUID
      @NSManaged public var name: String
      @NSManaged public var createAt: Date
  }
  
  struct Test1View: View {
      @Environment(\.managedObjectContext) var context
      var fetchRequest: FetchRequest&lt;Audio&gt; = FetchRequest&lt;Audio&gt;(entity: Audio.entity(), sortDescriptors: [NSSortDescriptor(key: "createAt", ascending: false)])
      var items: FetchedResults&lt;Audio&gt; { fetchRequest.wrappedValue }
      var body: some View {
          List {
              ForEach(items) { item in
                  HStack {
                      Text("\(item.name)")
                  }
              }.onDelete(perform: { indexSet in
                  let index = indexSet.first!
                  let item = self.items[index]
                  self.context.delete(item)
                  try? self.context.save()
              })
          }
      }
  }
  </code></pre>