# Objective
Fix warnings:
```rs
warning: variable does not need to be mutable
--> /bevy/crates/bevy_app/src/plugin_group.rs:147:13
|
147 | let mut plugin_entry = self
| ----^^^^^^^^^^^^
| |
| help: remove this `mut`
|
= note: `#[warn(unused_mut)]` on by default
warning: variable does not need to be mutable
--> /bevy/crates/bevy_app/src/plugin_group.rs:161:13
|
161 | let mut plugin_entry = self
| ----^^^^^^^^^^^^
| |
| help: remove this `mut`
warning: `bevy_app` (lib) generated 2 warnings (run `cargo fix --lib -p bevy_app` to apply 2 suggestions)
warning: variable does not need to be mutable
--> /bevy/crates/bevy_render/src/view/window.rs:126:13
|
126 | ... let mut extracted_window = extracted_windows.entry(entity).or_insert(Extracte...
| ----^^^^^^^^^^^^^^^^
|
= note: `#[warn(unused_mut)]` on by default
warning: `bevy_render` (lib) generated 1 warning (run `cargo fix --lib -p bevy_render` to apply 1 suggestion)
```
## Solution
- Remove the mut keyword in those variables.
a21bc41cca