title: Xcode 11 beta 3 crashing when using NavigationLink, @EnvironmentObject and List together
body: <p>I've got a strange crash in <strong>SwiftUI / Xcode 11 beta 3</strong> with code like the one below (I've kept only the bare minimum to show the behavior):</p>
  
  <pre class="lang-swift prettyprint-override"><code>import SwiftUI
  import Combine
  
  final class AppData: BindableObject  {
      let didChange = PassthroughSubject&lt;AppData, Never&gt;()
  
      init() { }
  }
  
  struct ContentView : View {
      var body: some View {
          NavigationView {
              NavigationLink(destination: DetailView() ) {
                  Text("link")
              }
          }
      }
  }
  
  struct DetailView : View {
      @EnvironmentObject var appData: AppData
  //  @ObjectBinding var appData = AppData() -&gt; Works 
  
      var body: some View {
          List {
              Text("A")
              Text("B")
              Text("C")
          }
      }
  }
  
  </code></pre>
  
  <p>The <code>BindableObject</code> is injected in <code>SceneDelegate.swift</code> like this:</p>
  
  <pre class="lang-swift prettyprint-override"><code>....
          // Use a UIHostingController as window root view controller
          if let windowScene = scene as? UIWindowScene {
              let window = UIWindow(windowScene: windowScene)
              window.rootViewController = UIHostingController(rootView: ContentView()
                                             .environmentObject(AppData()))
              self.window = window
              window.makeKeyAndVisible()
          }
  ....
  </code></pre>
  
  <p>When following the <code>NavigationLink</code> it crashes with </p>
  
  <p><code>Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)</code></p>
  
  <p>If I remove the <code>List</code> view from the detail view it works OK. The same if I use <code>@ObjectBinding</code> instead (like in the commented line in my code).</p>
  
  <p>The same code used to work in previous betas. </p>