Issue with despawn_recursive() combined with parent.spawn_scene()

[Indy2222]

I am recursively despawning an entity in a system executed during CoreStage::PreUpdate:

commands.entity(entity).despawn_recursive();

In a different system, executed during CoreStage::Update, I am accessing that entity and spawning an (already loaded) scene as a child. The code below executes (several frames) before the code above:

commands
    .entity(entity)
    .insert(Ready)
    .with_children(|parent| {
        parent.spawn_scene(cache.get(*object_type).scene());
    });

This sometimes leads to a panic: thread 'main' panicked at 'Entity 1648v0 does not exist'.

I suspect that this is due to parent.spawn_scene() taking long time and somehow accessing the entity.

Could someone point me out to what I am doing wrong or how to solve that situation?

[DJMcNab]

I believe this to be a duplicate of #3195

[Indy2222]

Thank you for pointing out that issue. It seems very similar in my case.

However, the scene is already loaded at the time I spawn it (server.get_load_state(handle) is LoadState::Loaded for the given handle) and the error happens even several seconds after I spawn the scene. It seems very non-deterministic, because most of the time I can do the spawn-despawn in a quick succession with no problem.

[Indy2222]

I need to apologies, my previous comment was not entirely correct.

I executed the two systems twice (probably during two consecutive frames) due to the fact that I got twice the same key keys.get_just_pressed().last() from Input<KeyCode>. Which, by itself, seems like strange behavior.

Thus it seems that my issue is really a manifestation of #3195.