Bevy + Avian3D in a fully headless setup crash

[tajo48]

I am trying to run Bevy + Avian3D in a fully headless setup (no windowing, no rendering), using MinimalPlugins and ScheduleRunnerPlugin::run_once().

This minimal example compiles and starts, but panics immediately at runtime with a Bevy ECS validation error:

Parameter `...::messages` failed validation: Message not initialized

Full minimal repro:

use avian3d::prelude::*;
use bevy::{app::ScheduleRunnerPlugin, prelude::*};

fn main() {
    App::new()
        .add_plugins(MinimalPlugins.set(ScheduleRunnerPlugin::run_once()))
        .add_plugins((
            TransformPlugin,
            bevy::asset::AssetPlugin::default(),
            bevy::scene::ScenePlugin,
        ))
        .init_resource::<Assets<Mesh>>()
        .add_systems(Update, hello_world_system)
        .add_plugins(PhysicsPlugins::default())
        .run();
}

fn hello_world_system() {
    println!("hello world");
}

[dependencies]
avian3d = "0.5.0"
bevy = "0.18.0"

The panic comes from bevy_ecs complaining about an uninitialized Message parameter (suggesting Option<T> / If<T>), but this happens before I register any Avian-specific systems myself.

Is this a known limitation of Avian in headless / MinimalPlugins setups, or am I missing a required plugin or resource initialization for physics-only use? Any guidance on the minimal plugin set needed for Avian without rendering would be appreciated.

Perhaps related to #505

[tajo48]

This is the fix:

use avian3d::prelude::*;
use bevy::{app::ScheduleRunnerPlugin, prelude::*};
fn main() {
    App::new()
        .add_plugins(MinimalPlugins.set(ScheduleRunnerPlugin::run_once()))
        .add_plugins((
            TransformPlugin,
            bevy::asset::AssetPlugin::default(),
            bevy::scene::ScenePlugin,
        ))
        .init_resource::<Assets<Mesh>>()
        .add_systems(Update, hello_world_system)
        .add_plugins(PhysicsPlugins::default())
        .add_message::<AssetEvent<Mesh>>()
        .run();
}
fn hello_world_system() {
    println!("hello world");
}

Thanks for https://github.com/Veritius for the hint