# Objective
Fixes#8215 and #8152. When systems panic, it causes the main thread to
panic as well, which clutters the output.
## Solution
Resolves the panic in the multi-threaded scheduler. Also adds an extra
message that tells the user the system that panicked.
Using the example from the issue, here is what the messages now look
like:
```rust
use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Update, panicking_system)
.run();
}
fn panicking_system() {
panic!("oooh scary");
}
```
### Before
```
Compiling bevy_test v0.1.0 (E:\Projects\Rust\bevy_test)
Finished dev [unoptimized + debuginfo] target(s) in 2m 58s
Running `target\debug\bevy_test.exe`
2023-03-30T22:19:09.234932Z INFO bevy_diagnostic::system_information_diagnostics_plugin::internal: SystemInfo { os: "Windows 10 Pro", kernel: "19044", cpu: "AMD Ryzen 5 2600 Six-Core Processor", core_count: "6", memory: "15.9 GiB" }
thread 'Compute Task Pool (5)' panicked at 'oooh scary', src\main.rs:11:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'Compute Task Pool (5)' panicked at 'A system has panicked so the executor cannot continue.: RecvError', E:\Projects\Rust\bevy\crates\bevy_ecs\src\schedule\executor\multi_threaded.rs:194:60
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', E:\Projects\Rust\bevy\crates\bevy_tasks\src\task_pool.rs:376:49
error: process didn't exit successfully: `target\debug\bevy_test.exe` (exit code: 101)
```
### After
```
Compiling bevy_test v0.1.0 (E:\Projects\Rust\bevy_test)
Finished dev [unoptimized + debuginfo] target(s) in 2.39s
Running `target\debug\bevy_test.exe`
2023-03-30T22:11:24.748513Z INFO bevy_diagnostic::system_information_diagnostics_plugin::internal: SystemInfo { os: "Windows 10 Pro", kernel: "19044", cpu: "AMD Ryzen 5 2600 Six-Core Processor", core_count: "6", memory: "15.9 GiB" }
thread 'Compute Task Pool (5)' panicked at 'oooh scary', src\main.rs:11:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Encountered a panic in system `bevy_test::panicking_system`!
Encountered a panic in system `bevy_app::main_schedule::Main::run_main`!
error: process didn't exit successfully: `target\debug\bevy_test.exe` (exit code: 101)
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François <mockersf@gmail.com>
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