Want to acces 2 components for my community demo game: cannot borrow world as mutable because it is also borrowed as immutable

[Retrodad0001]

I'm new to rust and bevy, so it could be that I'm missing something.

Public repo: https://github.com/Retrodad0001/evil_dungeon

I want to create a simple but polished game for the community to learn rust, bevy, and the "ECS way" of designing a game and share that knowledge with everyone.

error[E0502]: cannot borrow world as mutable because it is also borrowed as immutable
--> src\core\screen_playing.rs:289:52
|
285 | let entity_a_world_ref: EntityRef = world.entity(entity_a);
| ----- immutable borrow occurs here
...
289 | let mut entity_world_mut: EntityWorldMut = world.entity_mut(entity_b);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
...
293 | if component_damage_option.is_none() || component_health_option.is_none() {
| ----------------------- immutable borrow later used here

pub(crate) fn collision_event_handle_damage_dealing_and_health_for_all(
    mut event_collision_detected: EventReader<EventCollisionDetected>,
    mut event_actor_is_killed: EventWriter<EventActorIsKilled>,
    mut world: World,
) {
    for collision_event in event_collision_detected.read() {
        let entity_a: Entity = collision_event.entity_a;
        let entity_b: Entity = collision_event.entity_b;

        let entity_a_world_ref: EntityRef = world.entity(entity_a);
        let component_damage_option =
            entity_a_world_ref.get::<ComponentCanDealDamage>();

        let mut entity_world_mut: EntityWorldMut = world.entity_mut(entity_b);
        let component_health_option =
            entity_world_mut.get_mut::<ComponentHasHealth>();

        if component_damage_option.is_none() || component_health_option.is_none() {
            continue;
        }

        let mut health  = component_health_option.unwrap();
        let damage   = component_damage_option.unwrap();

        health.current_health -= damage.damage_amount;

        if health.current_health <= 0 {
            event_actor_is_killed.send(EventActorIsKilled::new(entity_b));
        }
    }
}

[MrGVSV]

Is collision_event_handle_damage_dealing_and_health_for_all a system? If so, I’d recommend using a Query instead of World so that you can use something like Query::get_many_mut to fetch both entities without breaking Rust's mutability rules.