Serializing Scenes error from AtomicBool | Bevy | Page 1

worthy monolith Mar 11, 2026, 1:57 AM

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Bevy 0.17.3 (downgraded to use Rapier)

The following code:


fn main() {
    App::new()
        .insert_resource(ClearColor(Color::linear_rgb(0.2, 0.4, 1.0)))
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, save_scene)
        .run();
}

fn save_scene(world: &mut World) {
    let registry = world.resource::<AppTypeRegistry>();
    let scene = DynamicScene::from_world(world);
    let serialized_scene = scene.serialize(&registry.read());
    info!("{:?}", serialized_scene);
}```

Results in the following error:
```type `bevy_platform::sync::Arc<core::sync::atomic::AtomicBool>` did not register the `ReflectSerialize` or `ReflectSerializeWithRegistry` type data. For certain types, this may need to be registered manually using `register_type_data` (stack: `bevy_a11y::AccessibilityRequested` -> `bevy_platform::sync::Arc<core::sync::atomic::AtomicBool>`)```

I don't really know where the call to AtomicBool comes from, and I'm trying to find a workaround.

I have found a relevant github issue (https://github.com/bevyengine/bevy/issues/22816), but can anyone help me find a workaround in the meantime?

GitHub

bevyengine/bevy

A refreshingly simple data-driven game engine built in Rust - bevyengine/bevy

magic haven Mar 11, 2026, 3:16 AM

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Do you know where that atomic is being used in your stack? It’s most likely UI. You could maybe exclude it from your serialization

worthy monolith Mar 11, 2026, 3:19 AM

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I posted the entire project code. There is no ui, no camera, and in fact no entities.

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As stated, I have no idea where this atomic is in my stack

magic haven Mar 11, 2026, 3:20 AM

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You posted a zip, can you make a repo instead?

worthy monolith Mar 11, 2026, 3:21 AM

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I'm pretty certain I did not post a zip

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The code is contained in the text body of the post

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I'm working on a minimum reproduction of the error. I'll post that as a repo in a minute

magic haven Mar 11, 2026, 3:23 AM

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worthy monolith The code is contained in the text body of the post

Oh sorry the GitHub issue had one, not you. My bad.

worthy monolith Mar 11, 2026, 3:24 AM

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Ah ok

magic haven Mar 11, 2026, 3:24 AM

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worthy monolith I'm pretty certain I did not post a zip

What OS Platform are you building for? Bevy uses inventory for compile time linking reflection types.

worthy monolith Mar 11, 2026, 3:25 AM

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Windows 11 currently, as that's what I'm using

magic haven Mar 11, 2026, 3:28 AM

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worthy monolith Windows 11 currently, as that's what I'm using

Have you compiled with reflection feature(s) on?

worthy monolith Mar 11, 2026, 3:29 AM

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Not yet. I didn't know about that feature. I'll try it

radiant basin Mar 11, 2026, 5:56 AM

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disallow the AccessibilityRequested Resource

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though it'd probably be better to specifically include only the resources and components you definitely want saved

worthy monolith Mar 11, 2026, 6:14 AM

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I'm not familiar with that functionality. How would I do that, and where should I look in the docs to learn more?

radiant basin Mar 11, 2026, 6:56 AM

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DynamicScene

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*Builder

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can see what your current code uses at https://docs.rs/bevy_scene/0.18.1/src/bevy_scene/dynamic_scene.rs.html#51

dynamic_scene.rs - source

Source of the Rust file src/dynamic_scene.rs.

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and here's the builder docpage https://docs.rs/bevy_scene/0.18.1/bevy_scene/struct.DynamicSceneBuilder.html for convenience

DynamicSceneBuilder in bevy_scene - Rust

A DynamicScene builder, used to build a scene from a World by extracting some entities and resources.

magic haven Mar 11, 2026, 7:26 AM

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radiant basin though it'd probably be better to specifically include only the resources and co...

Unrelated to this topic, but in general I find the concept of just moving data from world to save file to be.... easy but fragile.
I rather move data out of the world and serialize and deserialize manually using serde instead.
By default Bevy would snapshot the entire world basically.
But generally as a developer you want the state of the world, not individual components and entities.

radiant basin Mar 11, 2026, 7:28 AM

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my save system's just settings and a character profile, no reflection
if i actually wanted savestates i'd still use an allowlist manually though

magic haven Mar 11, 2026, 7:29 AM

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Yeah but that's far more cumbersome than just <save_these>

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https://docs.rs/bevy/latest/bevy/reflect/serde/struct.TypedReflectDeserializer.html#method.with_processor
https://docs.rs/bevy/latest/bevy/reflect/serde/struct.TypedReflectSerializer.html

TypedReflectSerializer in bevy::reflect::serde - Rust

A serializer for reflected types whose type will be known during deserialization.

TypedReflectDeserializer in bevy::reflect::serde - Rust

A deserializer for reflected types whose TypeRegistration is known.

radiant basin Mar 11, 2026, 7:29 AM

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for instance if you save all the physics components in avian you'll have problems when you load those entities, since it has a desynced state

magic haven Mar 11, 2026, 7:30 AM

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radiant basin for instance if you save all the physics components in avian you'll have problem...

Exactly.

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So now you're wrangling complex interfaces and weird methods name instead of <ON_SAVE> move data from Res/components to HashMap and serialize it.

radiant basin Mar 11, 2026, 7:39 AM

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can do that with a DynamicScene

magic haven Mar 11, 2026, 7:43 AM

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Yeah but the issue is when you're loading the dynamic scene into the world.

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You can just take it as is.
https://docs.rs/bevy/latest/bevy/prelude/struct.SceneSpawner.html#method.spawn_dynamic_sync

SceneSpawner in bevy::prelude - Rust

Handles spawning and despawning scenes in the world, either synchronously or batched through the scene_spawner_system.

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You might want to get bits of the data one by one, in order to make a complete spawn instead of spawning an incomplete DynamicScene

worthy monolith Mar 12, 2026, 8:26 PM

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To be honest, I'm probably just going to roll my own save system at this point. Marking as solved, though this solution will require a lot of work.

#Serializing Scenes error from AtomicBool