Resolved [1.0.0-exp.8]: EntityCommandBufferSystem.Singleton and ICustomBootstrap - HOW?

Got a very simple ICustomBootstrap and cannot figure out how the get the EntityCommandBufferSystem Singletons into the second world: as you can see in the picture: one world has two Singletons, and the other zero. Obviously the call to SystemAPI.GetSingleton<Any EntityCommandBufferSystem.Singleton>() fails in both world as a consequence of that. Stupid mistake on my end or bug in Entities [1.0.0-exp.8]?

Code (CSharp):

1. public class LoadingWorldBootStrap : ICustomBootstrap
2. {
3.     public bool Initialize(string defaultWorldName)
4.     {
5.         World.DefaultGameObjectInjectionWorld = new World("My Default World");
6.         var anotherWorld = new World("AnotherWorld");
7.  
8.  
9.         var systems = DefaultWorldInitialization.GetAllSystems(WorldSystemFilterFlags.Default);
10.         DefaultWorldInitialization.AddSystemsToRootLevelSystemGroups(World.DefaultGameObjectInjectionWorld, systems);
11.         ScriptBehaviourUpdateOrder.AppendWorldToCurrentPlayerLoop(World.DefaultGameObjectInjectionWorld);
12.  
13.         DefaultWorldInitialization.AddSystemsToRootLevelSystemGroups(anotherWorld, systems);
14.         ScriptBehaviourUpdateOrder.AppendWorldToCurrentPlayerLoop(anotherWorld);
15.         return true;
16.     }
17. }

 

Never mind. Turns out everything was just fine and the issue above was a stupid mistake on my end after all. The following innocuous little line moved ALL entities from "anotherWorld" (which I use as a loading/staging World) to the Default World, INLCUDING the ECB singleton.

Code (CSharp):

1. _entityManager.MoveEntitiesFrom(anotherWorldEntityManager);

Which of course leads to a duplication of the ECB Singleton in the Default world, and 0 Singletons in "anotherWorld"