Ambiguity checker emits a lot of warnings with default plugins

[jDomantas]

Bevy version

0.5

Operating system & version

Windows 10

What you did

fn main() {
    App::build()
        .insert_resource(ReportExecutionOrderAmbiguities)
        .add_plugins(DefaultPlugins)
        .run();
}

What you expected to happen

No ambiguities reported.

What actually happened

My terminal was flooded with ambiguity warnings:

Apr 10 18:07:56.172  INFO bevy_ecs::schedule::stage: Execution order ambiguities detected, you might want to add an explicit dependency relation between some of these systems:                                                                                     
 * Parallel systems:                                                                                                                                                                                                                                                
 -- "&bevy_render::camera::active_cameras::active_cameras_system" and "&bevy_render::camera::camera::camera_system<bevy_render::camera::projection::OrthographicProjection>"                                                                                        
    conflicts: ["bevy_render::camera::camera::Camera"]                                                                                                                                                                                                              
 -- "&bevy_render::camera::active_cameras::active_cameras_system" and "&bevy_render::camera::camera::camera_system<bevy_render::camera::projection::PerspectiveProjection>"                                                                                         
    conflicts: ["bevy_render::camera::camera::Camera"]                                                                                                                                                                                                              
 -- "&bevy_render::camera::camera::camera_system<bevy_render::camera::projection::OrthographicProjection>" and "&bevy_render::camera::camera::camera_system<bevy_render::camera::projection::PerspectiveProjection>"                                                
    conflicts: ["bevy_render::camera::camera::Camera"]                                                                                                                                                                                                              
 -- "&bevy_ui::widget::text::text_system" and "&bevy_ui::widget::image::image_node_system"                                                                                                                                                                          
    conflicts: ["bevy_asset::assets::Assets<bevy_render::texture::texture::Texture>", "bevy_ui::ui_node::CalculatedSize"]                                                                                                                                           
 -- "&bevy_ui::widget::text::text_system" and "&bevy_text::text2d::text2d_system"                                                                                                                                                                                   
    conflicts: ["bevy_asset::assets::Assets<bevy_render::texture::texture::Texture>", "bevy_asset::assets::Assets<bevy_sprite::texture_atlas::TextureAtlas>", "bevy_asset::assets::Assets<bevy_text::font_atlas_set::FontAtlasSet>", "bevy_text::pipeline::TextPipel
ine<bevy_ecs::entity::Entity>"]                                                                                                                                                                                                                                     
 -- "&bevy_ui::widget::text::text_system" and "&bevy_sprite::sprite::sprite_system"                                                                                                                                                                                 
    conflicts: ["bevy_asset::assets::Assets<bevy_render::texture::texture::Texture>"]                                                                                                                                                                               
 -- "&bevy_ui::widget::image::image_node_system" and "&bevy_text::text2d::text2d_system"                                                                                                                                                                            
    conflicts: ["bevy_asset::assets::Assets<bevy_render::texture::texture::Texture>"]                                                                                                                                                                               
 -- "&bevy_ui::flex::flex_node_system" and "&bevy_transform::hierarchy::hierarchy_maintenance_system::parent_update_system"                                                                                                                                         
    conflicts: ["bevy_transform::components::children::Children"]                                                                                                                                                                                                   
 -- "&bevy_ui::update::ui_z_system" and "&bevy_transform::hierarchy::hierarchy_maintenance_system::parent_update_system"                                                                                                                                            
    conflicts: ["bevy_transform::components::children::Children"]                                                                                                                                                                                                   
 -- "&bevy_render::shader::shader_defs::asset_shader_defs_system<bevy_sprite::color_material::ColorMaterial>" and "&bevy_render::shader::shader_defs::asset_shader_defs_system<bevy_pbr::material::StandardMaterial>"                                               
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_text::text2d::text2d_system" and "&bevy_sprite::sprite::sprite_system"                                                                                                                                                                                   
    conflicts: ["bevy_asset::assets::Assets<bevy_render::texture::texture::Texture>"]                                                                                                                                                                               
 * Exclusive systems at start of stage:                                                                                                                                                                                                                             
 -- "bevy_winit::change_window" and "bevy_audio::audio_output::play_queued_audio_system<bevy_audio::audio_source::AudioSource>"                                                                                                                                     
                                                                                                                                                                                                                                                                    
Apr 10 18:07:56.214  INFO bevy_ecs::schedule::stage: Execution order ambiguities detected, you might want to add an explicit dependency relation between some of these systems:                                                                                     
 * Parallel systems:                                                                                                                                                                                                                                                
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::color_material::ColorMaterial>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_transform::component
s::global_transform::GlobalTransform>"                                                                                                                                                                                                                              
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::color_material::ColorMaterial>" and "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::textur
e_atlas::TextureAtlas>"                                                                                                                                                                                                                                             
    conflicts: ["bevy_render::renderer::render_resource::render_resource_bindings::AssetRenderResourceBindings", "bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                        
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::color_material::ColorMaterial>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::texture_atla
s::TextureAtlasSprite>"                                                                                                                                                                                                                                             
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::color_material::ColorMaterial>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_ui::ui_node::Node>" 
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::color_material::ColorMaterial>" and "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_pbr::material:
:StandardMaterial>"                                                                                                                                                                                                                                                 
    conflicts: ["bevy_render::renderer::render_resource::render_resource_bindings::AssetRenderResourceBindings", "bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                        
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::color_material::ColorMaterial>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::sprite::Spri
te>"                                                                                                                                                                                                                                                                
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_transform::components::global_transform::GlobalTransform>" and "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_s
prite::texture_atlas::TextureAtlas>"                                                                                                                                                                                                                                
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_transform::components::global_transform::GlobalTransform>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite:
:texture_atlas::TextureAtlasSprite>"                                                                                                                                                                                                                                
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_transform::components::global_transform::GlobalTransform>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_ui::ui_
node::Node>"                                                                                                                                                                                                                                                        
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_transform::components::global_transform::GlobalTransform>" and "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_p
br::material::StandardMaterial>"                                                                                                                                                                                                                                    
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_transform::components::global_transform::GlobalTransform>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite:
:sprite::Sprite>"                                                                                                                                                                                                                                                   
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::texture_atlas::TextureAtlas>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::texture_atlas:
:TextureAtlasSprite>"                                                                                                                                                                                                                                               
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::texture_atlas::TextureAtlas>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_ui::ui_node::Node>"   
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::texture_atlas::TextureAtlas>" and "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_pbr::material::S
tandardMaterial>"                                                                                                                                                                                                                                                   
    conflicts: ["bevy_render::renderer::render_resource::render_resource_bindings::AssetRenderResourceBindings", "bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                        
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_sprite::texture_atlas::TextureAtlas>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::sprite::Sprite
>"                                                                                                                                                                                                                                                                  
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::texture_atlas::TextureAtlasSprite>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_ui::ui_node::Node>"   
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::texture_atlas::TextureAtlasSprite>" and "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_pbr::material::S
tandardMaterial>"                                                                                                                                                                                                                                                   
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::texture_atlas::TextureAtlasSprite>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::sprite::Sprite
>"                                                                                                                                                                                                                                                                  
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::camera_node::camera_node_system" and "&bevy_render::render_graph::nodes::camera_node::camera_node_system"                                                                                                                   
    conflicts: ["bevy_render::camera::active_cameras::ActiveCameras"]                                                                                                                                                                                               
 -- "&bevy_render::render_graph::nodes::camera_node::camera_node_system" and "&bevy_render::render_graph::nodes::camera_node::camera_node_system"                                                                                                                   
    conflicts: ["bevy_render::camera::active_cameras::ActiveCameras"]                                                                                                                                                                                               
 -- "&bevy_render::render_graph::nodes::camera_node::camera_node_system" and "&bevy_render::render_graph::nodes::camera_node::camera_node_system"                                                                                                                   
    conflicts: ["bevy_render::camera::active_cameras::ActiveCameras"]                                                                                                                                                                                               
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_ui::ui_node::Node>" and "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_pbr::material::StandardMaterial>"       
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_ui::ui_node::Node>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::sprite::Sprite>"                      
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
 -- "&bevy_render::render_graph::nodes::render_resources_node::asset_render_resources_node_system<bevy_pbr::material::StandardMaterial>" and "&bevy_render::render_graph::nodes::render_resources_node::render_resources_node_system<bevy_sprite::sprite::Sprite>"  
    conflicts: ["bevy_render::pipeline::render_pipelines::RenderPipelines"]                                                                                                                                                                                         
                                                                                                                                                                                                                                                                    
Apr 10 18:07:56.238  INFO bevy_ecs::schedule::stage: Execution order ambiguities detected, you might want to add an explicit dependency relation between some of these systems:                                                                                     
 * Parallel systems:                                                                                                                                                                                                                                                
 -- "&bevy_render::pipeline::render_pipelines::draw_render_pipelines_system" and "&bevy_ui::widget::text::draw_text_system"                                                                                                                                         
    conflicts: ["bevy_asset::assets::Assets<bevy_render::shader::shader::Shader>", "bevy_asset::assets::Assets<bevy_render::pipeline::pipeline::PipelineDescriptor>", "bevy_render::pipeline::pipeline_compiler::PipelineCompiler", "bevy_render::renderer::render_r
esource::render_resource_bindings::RenderResourceBindings", "bevy_render::renderer::render_resource::render_resource_bindings::AssetRenderResourceBindings", "bevy_render::renderer::render_resource::shared_buffers::SharedBuffers", "bevy_render::draw::Draw"]    
 -- "&bevy_render::pipeline::render_pipelines::draw_render_pipelines_system" and "&bevy_text::text2d::draw_text2d_system"                                                                                                                                           
    conflicts: ["bevy_asset::assets::Assets<bevy_render::shader::shader::Shader>", "bevy_asset::assets::Assets<bevy_render::pipeline::pipeline::PipelineDescriptor>", "bevy_render::pipeline::pipeline_compiler::PipelineCompiler", "bevy_render::renderer::render_r
esource::render_resource_bindings::RenderResourceBindings", "bevy_render::renderer::render_resource::render_resource_bindings::AssetRenderResourceBindings", "bevy_render::renderer::render_resource::shared_buffers::SharedBuffers", "bevy_render::draw::Draw"]    
 -- "&bevy_ui::widget::text::draw_text_system" and "&bevy_text::text2d::draw_text2d_system"                                                                                                                                                                         
    conflicts: ["bevy_asset::assets::Assets<bevy_render::shader::shader::Shader>", "bevy_asset::assets::Assets<bevy_render::pipeline::pipeline::PipelineDescriptor>", "bevy_render::pipeline::pipeline_compiler::PipelineCompiler", "bevy_render::renderer::render_r
esource::render_resource_bindings::RenderResourceBindings", "bevy_render::renderer::render_resource::render_resource_bindings::AssetRenderResourceBindings", "bevy_render::renderer::render_resource::shared_buffers::SharedBuffers", "bevy_render::draw::Draw"]    

[TheRawMeatball]

Hmm, this issue seems like the correct place to continue the discussion that started in #1606 :)

[TehPers]

This actually is part of the reason I've created stages that come after CoreStage::PreUpdate, CoreStage::Update, and CoreStage::PostUpdate. It's easier to filter for ambiguities in my own systems when they're in different stages than the ones added by the default plugins. (Of course, there's still some situations where I need to throw systems in the core stages, for example with a custom camera.)

[jakobhellermann]

An easy solution would be to allow filtering the ambiguities, something like

app.insert_resource(ReportExecutionOrderAmbiguities::filter(|name| name.contains(env!("CARGO_PKG_NAME")))

would only display the ambiguities in the current crate.

In the future (probably when there is an editor) there could be an .ambiguityignore file which allows you to easily mark a lot of ambiguities as fine without littering ambiguity sets all over the code.

[TheRawMeatball]

Whoops, misclick 😅

[Ratysz]

The intended solution is to add all default systems into their own, private ambiguity set. This will need to be hardcoded; two options:

• Individually: every default system is ascribed with the ambiguity set, either one by one or through system sets if possible. This is the correct way, but it's a bit grating for Bevy development. However, new systems implemented during further development will be able to check themselves for conflicts trivially.
• Blanket: all systems present in the schedule when default things are initialized are automatically ascribed with the ambiguity set. This is minimally invasive, but we lose the use of the checker for Bevy development (if we don't do something else special to opt back in, of course). There's also the footgun of inserting user systems before default systems.

[alice-i-cecile]

Will be resolved-ish by #2766.