Wasm build hits panic on unwrap in `specialize_material_meshes`

[janhohenheim]

Bevy version

0.16.0

Relevant system information

`AdapterInfo { name: "Radeon R9 200 Series, or similar", vendor: 4098, device: 0, device_type: Other, driver: "", driver_info: "WebGL 2.0", backend: Gl }`

What you did

I'm upgrading the Foxtrot 3D template to 0.16.
This involves patching a bunch of dependencies, so I don't have a minimal reproduction here, sorry.
You can checkout the project at janhohenheim/foxtrot@c28ee97 to reproduce this; the next commit janhohenheim/foxtrot@1cc51ed patches the issue.

What went wrong

The upgrade runs on native, but on web (using bevy run web), when I click "play" and the actual level spawns, I run into a crash caused by this unwrap in material.rs.

stack trace (not very useful on wasm)

panicked at /home/hhh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bevy_pbr-0.16.0/src/material.rs:1023:79:
called `Option::unwrap()` on a `None` value

Stack:

__wbg_get_imports/imports.wbg.__wbg_new_8a6f238a6ece86ea@http://localhost:4000/build/foxtrot.js:1380:21
foxtrot-05b6f671dbcdb43c.wasm.__wbg_new_8a6f238a6ece86ea externref shim@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[197194]:0x4cbcaa6
foxtrot-05b6f671dbcdb43c.wasm.console_error_panic_hook::hook::h449ff00e3decfb05@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[18542]:0x27f9287
foxtrot-05b6f671dbcdb43c.wasm.core::ops::function::Fn::call::h7fa847e3e6a41c4c@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[286437]:0x4e5998c
foxtrot-05b6f671dbcdb43c.wasm.std::panicking::rust_panic_with_hook::h180665ecefa3250d@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[86888]:0x440e028
foxtrot-05b6f671dbcdb43c.wasm.std::panicking::begin_panic_handler::{{closure}}::h916bd27682fce156@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[94826]:0x45838bb
foxtrot-05b6f671dbcdb43c.wasm.std::sys::backtrace::__rust_end_short_backtrace::h5a76ddaceef1192e@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[280450]:0x4e4c08e
foxtrot-05b6f671dbcdb43c.wasm.rust_begin_unwind@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[155291]:0x4b7b7bb
foxtrot-05b6f671dbcdb43c.wasm.core::panicking::panic_fmt::h04e2482e563fa46a@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[155292]:0x4b7b7e8
foxtrot-05b6f671dbcdb43c.wasm.core::panicking::panic::hd88d80cbf1dd6e75@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[142129]:0x4aaadcf
foxtrot-05b6f671dbcdb43c.wasm.core::option::unwrap_failed::h88b8d8d71904b975@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[266334]:0x4e1eed5
foxtrot-05b6f671dbcdb43c.wasm.core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut::h1749bd496bf2e493@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[985]:0x6bfc75
foxtrot-05b6f671dbcdb43c.wasm.<bevy_ecs::system::schedule_system::InfallibleSystemWrapper<S> as bevy_ecs::system::system::System>::run_unsafe::h43d3f808b57c098b@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[1147]:0x7c4358
foxtrot-05b6f671dbcdb43c.wasm.bevy_ecs::schedule::executor::__rust_begin_short_backtrace::run_unsafe::hec52edd22d34ae03@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[165375]:0x4bdf3d7
foxtrot-05b6f671dbcdb43c.wasm.<bevy_ecs::schedule::executor::single_threaded::SingleThreadedExecutor as bevy_ecs::schedule::executor::SystemExecutor>::run::hf6bdd15f0157c4b9@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[4408]:0x13f972c
foxtrot-05b6f671dbcdb43c.wasm.bevy_ecs::schedule::schedule::Schedule::run::he364f038224a5610@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[69305]:0x3ff5c82
foxtrot-05b6f671dbcdb43c.wasm.bevy_ecs::world::World::schedule_scope::h846d07c248f9ff45@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[18468]:0x27e8db0
foxtrot-05b6f671dbcdb43c.wasm.bevy_app::sub_app::SubApps::update::h4f101dd40a46b35e@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[31324]:0x3105847
foxtrot-05b6f671dbcdb43c.wasm.bevy_app::app::App::update::hc15555740baf6ac3@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[43089]:0x36f3def
foxtrot-05b6f671dbcdb43c.wasm.bevy_winit::state::WinitAppRunnerState<T>::redraw_requested::he166ee6a39817b96@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[601]:0x32dc5d
foxtrot-05b6f671dbcdb43c.wasm.<bevy_winit::state::WinitAppRunnerState<T> as winit::application::ApplicationHandler<T>>::about_to_wait::h2bd8c7a464caaa5f@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[1927]:0xb8e2e2
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::event_loop::EventLoop<T>::spawn::{{closure}}::h6c339afa9fc20c4d@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[25185]:0x2d24f4d
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::event_loop::runner::Shared::handle_event::hd45211b8eb6129f8@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[10146]:0x1ebb8b0
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::event_loop::runner::Shared::request_redraw::hd4c16eefbc5e498b@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[19129]:0x287dae8
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::web_sys::animation_frame::AnimationFrameHandler::on_animation_frame::{{closure}}::h0aa9faa9ef9289fb@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[165163]:0x4bddd15
foxtrot-05b6f671dbcdb43c.wasm.<dyn core::ops::function::FnMut<()>+Output = R as wasm_bindgen::closure::WasmClosure>::describe::invoke::hffed8617854b4e71@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[164163]:0x4bd5d71
__wbg_adapter_42@http://localhost:4000/build/foxtrot.js:271:10
real@http://localhost:4000/build/foxtrot.js:183:20
FrameRequestCallback*__wbg_get_imports/imports.wbg.__wbg_requestAnimationFrame_d7fd890aaefc3246/<@http://localhost:4000/build/foxtrot.js:1618:26
handleError@http://localhost:4000/build/foxtrot.js:34:18
__wbg_get_imports/imports.wbg.__wbg_requestAnimationFrame_d7fd890aaefc3246@http://localhost:4000/build/foxtrot.js:1617:84
foxtrot-05b6f671dbcdb43c.wasm.__wbg_requestAnimationFrame_d7fd890aaefc3246 externref shim@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[266367]:0x4e1f09e
foxtrot-05b6f671dbcdb43c.wasm.web_sys::features::gen_Window::Window::request_animation_frame::hcf7388c89a946804@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[143486]:0x4ac21d3
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::window::Inner::request_redraw::hd0fdfb2ac048db72@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[74166]:0x41347b5
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::async::dispatcher::Dispatcher<T>::dispatch::h985bdb3250418c78@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[94219]:0x4569c8f
foxtrot-05b6f671dbcdb43c.wasm.bevy_winit::state::WinitAppRunnerState<T>::redraw_requested::he166ee6a39817b96@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[601]:0x330578
foxtrot-05b6f671dbcdb43c.wasm.<bevy_winit::state::WinitAppRunnerState<T> as winit::application::ApplicationHandler<T>>::about_to_wait::h2bd8c7a464caaa5f@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[1927]:0xb8e2e2
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::event_loop::EventLoop<T>::spawn::{{closure}}::h6c339afa9fc20c4d@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[25185]:0x2d24f4d
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::event_loop::runner::Shared::handle_event::hd45211b8eb6129f8@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[10146]:0x1ebb8b0
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::event_loop::runner::Shared::send_events::h93cca2cb66b2cfb9@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[15041]:0x24a65aa
foxtrot-05b6f671dbcdb43c.wasm.winit::platform_impl::web::event_loop::runner::Shared::set_listener::{{closure}}::h6e7e3c67fbbe35fd@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[40484]:0x35c450a
foxtrot-05b6f671dbcdb43c.wasm.<dyn core::ops::function::FnMut<(A,)>+Output = R as wasm_bindgen::closure::WasmClosure>::describe::invoke::h288c2e8006ea36c0@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[163054]:0x4bcc9cc
foxtrot-05b6f671dbcdb43c.wasm.closure95225 externref shim@http://localhost:4000/build/foxtrot_bg.wasm:wasm-function[196659]:0x4cba323
__wbg_adapter_39@http://localhost:4000/build/foxtrot.js:267:10
real@http://localhost:4000/build/foxtrot.js:183:20

Additional information

Relevant PBR code:

pub fn specialize_material_meshes(...) { 
// ...
  let entity_tick = entity_specialization_ticks.get(visible_entity).unwrap();

And here's some logs:

INFO /home/hhh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bevy_render-0.16.0/src/renderer/mod.rs:200 AdapterInfo { name: "Radeon R9 200 Series, or similar", vendor: 4098, device: 0, device_type: Other, driver: "", driver_info: "WebGL 2.0", backend: Gl } foxtrot.js:1255:21
INFO /home/hhh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bevy_render-0.16.0/src/batching/gpu_preprocessing.rs:1126 GPU preprocessing is not supported on this device. Falling back to CPU preprocessing. foxtrot.js:1255:21
WARN /home/hhh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bevy_core_pipeline-0.16.0/src/oit/resolve/mod.rs:83 OrderIndependentTransparencyPlugin not loaded. GPU lacks support: DownlevelFlags::FRAGMENT_WRITABLE_STORAGE. foxtrot.js:1255:21
WARN /home/hhh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bevy_pbr-0.16.0/src/ssao/mod.rs:92 ScreenSpaceAmbientOcclusionPlugin not loaded. GPU lacks support: TextureFormat::R16Float does not support TextureUsages::STORAGE_BINDING. foxtrot.js:1255:21
WARN /home/hhh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bevy_pbr-0.16.0/src/atmosphere/mod.rs:170 AtmospherePlugin not loaded. GPU lacks support for compute shaders. foxtrot.js:1255:21
INFO /home/hhh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bevy_dev_tools-0.16.0/src/states.rs:17 foxtrot::screens::Screen transition: None => Some(Splash) foxtrot.js:1255:21
INFO /home/hhh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bevy_core_pipeline-0.16.0/src/dof/mod.rs:824 Disabling depth of field on this platform because depth textures aren't supported correctly

[janhohenheim]

Update: cannot reproduce this on WebGPU, but instead the world just renders as grey. Don't know if that's related 🤷‍♂

[janhohenheim]

Update: disabling asset preloading for some... sound effects?! fixed it: janhohenheim/foxtrot@1cc51ed

[janhohenheim]

Update 2: This is getting weirder by the minute.
The sound effects are for some burning logs in a hearth fire. Note that the bug fix is not disabling the sounds themselves, but just not preloading them ahead of time
but
This exact issue also comes up when I have no burning logs at all. This crashes:

But when I make the single floor transparent, it does not crash:

Things that crash:

• Have visible floors and no burning logs
• Have visible floors and spawn burning logs with sounds preloaded

Things that don't crash:

• Have visible floors and spawn burning logs with sounds not preloaded
• Have invisible floors and spawn burning logs with sounds preloaded

[janhohenheim]

Labeling this as unsound because this smells like undefined behavior to me. Feel free to remove the label if you disagree