Seg Fault on MacOs

[roboteng]

Bevy version

0.9.0

[Optional] Relevant system information

MacOS version: 13.0.1 (22A400)
Intel i7 (not M1/M2)

Rust version:
rustc 1.65.0 (897e37553 2022-11-02)

What you did

I found this on a more complicated program, but I found the same seg fault on this:

use bevy::prelude::*;

fn main() {
    App::new().add_plugins(DefaultPlugins).run();
}

What went wrong

It runs, but crashes in runtime, and gives this error:

Finished dev [optimized + debuginfo] target(s) in 1.70s
     Running `target/debug/bevy_test`
[1]    45941 segmentation fault  cargo run

• what were you expecting?

To show the basic window

• what actually happened?

A segfault

Additional information

if MinimalPlugins is used instead, then everything works as expected. It's obviously something that is specific to DefaultPlugins

Additionally, I was able to run bevy 0.8.1 fine, but I ran into this issue when switching to 0.9.0

I did some quick searches in winit's and wgpu's repos, and didn't see anything related to seg faults

I'm not 100% sure what commands I can run to get more information, but I'll try what people suggest

[james7132]

Can you try to narrow down which potential plugin is causing this? DefaultPlugins includes quite a few items that could be causing this crash.

[superdump]

Could you run bevy in a debugger and get a backtrace of where it segfaults?

[roboteng]

The issue seems to be in the RednerPlugin

use bevy::{prelude::*, render::RenderPlugin, window::WindowPlugin};

fn main() {
    App::new()
        .add_plugin(WindowPlugin::default())
        .add_plugin(AssetPlugin::default())
        .add_plugin(RenderPlugin)
        .run();
}

This seg faults, but if I comment out the RenderPlugin line, then it doesn't. I'll try and look into this some more, but I haven't touched these plugins before

Also, here's the stack trace I got from LLDB

_platform_memmove$VARIANT$Haswell (@_platform_memmove$VARIANT$Haswell:63)
core::intrinsics::copy_nonoverlapping (@<&mut W as core::fmt::Write>::write_str:22)
alloc::vec::Vec<T,A>::append_elements (@<&mut W as core::fmt::Write>::write_str:19)
<alloc::vec::Vec<T,A> as alloc::vec::spec_extend::SpecExtend<&T,core::slice::iter::Iter<T>>>::spec_extend (@<&mut W as core::fmt::Write>::write_str:12)
alloc::vec::Vec<T,A>::extend_from_slice (@<&mut W as core::fmt::Write>::write_str:12)
alloc::string::String::push_str (@<&mut W as core::fmt::Write>::write_str:12)
<alloc::string::String as core::fmt::Write>::write_str (@<&mut W as core::fmt::Write>::write_str:12)
<&mut W as core::fmt::Write>::write_str (@<&mut W as core::fmt::Write>::write_str:12)
core::fmt::write (@core::fmt::write:117)
core::fmt::Write::write_fmt (@<std::panicking::begin_panic_handler::PanicPayload as core::panic::BoxMeUp>::get:32)
std::panicking::begin_panic_handler::PanicPayload::fill::{{closure}} (@<std::panicking::begin_panic_handler::PanicPayload as core::panic::BoxMeUp>::get:16)
core::option::Option<T>::get_or_insert_with (@<std::panicking::begin_panic_handler::PanicPayload as core::panic::BoxMeUp>::get:11)
std::panicking::begin_panic_handler::PanicPayload::fill (@<std::panicking::begin_panic_handler::PanicPayload as core::panic::BoxMeUp>::get:11)
<std::panicking::begin_panic_handler::PanicPayload as core::panic::BoxMeUp>::get (@<std::panicking::begin_panic_handler::PanicPayload as core::panic::BoxMeUp>::get:5)
std::panicking::rust_panic_with_hook (@std::panicking::rust_panic_with_hook:41)
std::panicking::begin_panic_handler::{{closure}} (@std::panicking::begin_panic_handler::{{closure}}:57)
std::sys_common::backtrace::__rust_end_short_backtrace (@std::sys_common::backtrace::__rust_end_short_backtrace:14)
rust_begin_unwind (@rust_begin_unwind:30)
core::panicking::panic_fmt (@core::panicking::panic_fmt:15)
core::panicking::panic_display (@core::panicking::panic_display:18)
wgpu_hal::metal::adapter::<impl wgpu_hal::metal::PrivateCapabilities>::new (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-hal-0.14.1/src/metal/adapter.rs:485)
wgpu_hal::metal::AdapterShared::new (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-hal-0.14.1/src/metal/mod.rs:263)
<wgpu_hal::metal::Instance as wgpu_hal::Instance<wgpu_hal::metal::Api>>::enumerate_adapters::{{closure}} (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-hal-0.14.1/src/metal/mod.rs:112)
core::iter::adapters::map::map_fold::{{closure}} (@<core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::fold:30)
core::iter::traits::iterator::Iterator::fold (@<core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::fold:28)
<core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::fold (@<core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::fold:22)
core::iter::traits::iterator::Iterator::for_each (@alloc::vec::in_place_collect::<impl alloc::vec::spec_from_iter::SpecFromIter<T,I> for alloc::vec::Vec<T>>::from_iter:87)
<alloc::vec::Vec<T,A> as alloc::vec::spec_extend::SpecExtend<T,I>>::spec_extend (@alloc::vec::in_place_collect::<impl alloc::vec::spec_from_iter::SpecFromIter<T,I> for alloc::vec::Vec<T>>::from_iter:73)
<alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter (@alloc::vec::in_place_collect::<impl alloc::vec::spec_from_iter::SpecFromIter<T,I> for alloc::vec::Vec<T>>::from_iter:70)
alloc::vec::in_place_collect::<impl alloc::vec::spec_from_iter::SpecFromIter<T,I> for alloc::vec::Vec<T>>::from_iter (@alloc::vec::in_place_collect::<impl alloc::vec::spec_from_iter::SpecFromIter<T,I> for alloc::vec::Vec<T>>::from_iter:23)
<alloc::vec::Vec<T> as core::iter::traits::collect::FromIterator<T>>::from_iter (@<wgpu_hal::metal::Instance as wgpu_hal::Instance<wgpu_hal::metal::Api>>::enumerate_adapters:22)
core::iter::traits::iterator::Iterator::collect (@<wgpu_hal::metal::Instance as wgpu_hal::Instance<wgpu_hal::metal::Api>>::enumerate_adapters:15)
<wgpu_hal::metal::Instance as wgpu_hal::Instance<wgpu_hal::metal::Api>>::enumerate_adapters (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-hal-0.14.1/src/metal/mod.rs:108)
wgpu_core::instance::<impl wgpu_core::hub::Global<G>>::request_adapter::gather (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-core-0.14.0/src/instance.rs:727)
wgpu_core::instance::<impl wgpu_core::hub::Global<G>>::request_adapter (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-core-0.14.0/src/instance.rs:771)
<wgpu::backend::direct::Context as wgpu::Context>::instance_request_adapter (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.14.0/src/backend/direct.rs:861)
wgpu::Instance::request_adapter (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.14.0/src/lib.rs:1795)
bevy_render::renderer::initialize_renderer::{{closure}} (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/bevy_render-0.9.0/src/renderer/mod.rs:118)
<core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll (@<core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll:13)
futures_lite::future::block_on::{{closure}} (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-lite-1.12.0/src/future.rs:89)
std::thread::local::LocalKey<T>::try_with (@std::thread::local::LocalKey<T>::with:17)
std::thread::local::LocalKey<T>::with (@std::thread::local::LocalKey<T>::with:13)
futures_lite::future::block_on (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-lite-1.12.0/src/future.rs:79)
<bevy_render::RenderPlugin as bevy_app::plugin::Plugin>::build (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/bevy_render-0.9.0/src/lib.rs:161)
bevy_app::app::App::add_boxed_plugin (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/bevy_app-0.9.0/src/app.rs:859)
bevy_app::app::App::add_plugin (/Users/tws/.cargo/registry/src/github.com-1ecc6299db9ec823/bevy_app-0.9.0/src/app.rs:839)
bevy_test::main (/Users/tws/develop/bevy_test/src/main.rs:6)
core::ops::function::FnOnce::call_once (@std::sys_common::backtrace::__rust_begin_short_backtrace:6)
std::sys_common::backtrace::__rust_begin_short_backtrace (@std::sys_common::backtrace::__rust_begin_short_backtrace:5)
std::rt::lang_start::{{closure}} (@std::rt::lang_start::{{closure}}:7)
core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once (@std::rt::lang_start_internal:170)
std::panicking::try::do_call (@std::rt::lang_start_internal:169)
std::panicking::try (@std::rt::lang_start_internal:169)
std::panic::catch_unwind (@std::rt::lang_start_internal:169)
std::rt::lang_start_internal::{{closure}} (@std::rt::lang_start_internal:169)
std::panicking::try::do_call (@std::rt::lang_start_internal:169)
std::panicking::try (@std::rt::lang_start_internal:169)
std::panic::catch_unwind (@std::rt::lang_start_internal:169)
std::rt::lang_start_internal (@std::rt::lang_start_internal:169)
main (@main:14)
start (@start:532)

The seems to point towards wgpu::metal as causing the panic.

[sambriels]

I can reproduce the seg fault on macOS 13.0.1 with bevy 0.9.0 and can also confirm it does not occur on bevy 0.8.1.

If I turn off most optimisations for packages

[profile.dev.package."*"]
opt-level = 1

the seg fault does not occur. @roboteng could you give that a try and see if that is also the case for you?

I am trying to disable optimisation for specific packages to track down the issue in more detail, but so far I have not been able to get it working without setting the opt-level = 1 for every package. I will try to delve deeper once I get some free time.

I also tried stepping through the code with the debugger, and noticed that the seg fault sometimes does not occur then. So there may be a race condition somewhere. The error seems to occur while gathering and handling the device adapters. I just started out with bevy and rust, so my knowledge is a bit limited. If anyone has any additional pointers to solutions I am all for trying them.

Edit: I can reproduce it with this minimal example

use bevy::{prelude::*, render::RenderPlugin};

fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        .add_plugin(WindowPlugin::default())
        .add_plugin(AssetPlugin::default())
        .add_plugin(RenderPlugin)
        .add_plugin(ImagePlugin::default())
        .run();
}

with optimisations turned on the seg fault occurs, without it runs fine. If I remove RenderPlugin it works also with optimisations turned on

[mockersf]

does it segfault also with --release?

[sambriels]

No seg fault when running with --release either. I did notice that eventhough it does not seg fault, no window is actually spawned. This is also the case in the optimised regular cargo dev run. I am not sure what other plugins need to be added as a minimum to actually spawn a window though.

[roboteng]

Hmm, it seems like it's been fixed. Using just the DefaultPlugins I don't get the error anymore. When I tried with WIndowPlugin, AssetPlugin, and RenderPlugin, I still got an error, but the main point of using DefaultPlugins seems to be fixed. Doing a simple cargo run vs cargo run --release doesn't make a difference either, currently. I think there may still be some issues if you don't include all the correct plugins, but that seems expected to me

Update: it seems like the error is only present when optimizing compile times with:

[profile.dev.package."*"]
opt-level = 3

If that optimization isn't present, then things work fine

[1moeses]

Still not fixed for me on Mac (Ventura 13.0.1, 2019). I get segfaults with the --release flag and

[profile.dev.package."*"]
opt-level = 3

But this example runs fine without the --release flag and without opt-level = 3:

Cargo.toml:

[package]
name = "test"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[profile.dev]
opt-level = 1

[profile.dev.package."*"]
opt-level = 1

[dependencies]
bevy = { version = "0.9.1", features = ["dynamic"] }
bevy-inspector-egui = "0.14.0"

Min example:

use bevy::{prelude::*, render::RenderPlugin};

fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        .add_plugin(WindowPlugin::default())
        .add_plugin(AssetPlugin::default())
        .add_plugin(RenderPlugin)
        .add_plugin(ImagePlugin::default())
        .run();
}