# Biome @biomejs/biome@2.5.8 — Release & Upgrade Intelligence
- **Product:** Biome (https://biomejs.dev)
- **Version:** @biomejs/biome@2.5.8
- **Released:** Aug 11, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/biome/updates/biomejs-biome-2.5.8/

## Executive Summary (TL;DR)
Biome @biomejs/biome@2.5.8. Source highlight: Added a new nursery rule `useReactCompiler`, which reports diagnostics from React Compiler lint mode.

## Bug Fixes
- Added a new nursery rule `useReactCompiler`, which reports diagnostics from React Compiler lint mode.
- Improved performance of `noImportCycles`.
- Added the nursery rule `noSvelteLegacyConst`, which disallows legacy Svelte `{@const}` tags and recommends declaration tags with `$derived()`.
- Fixed #11250: `useAwait` no longer reports async functions that contain an `await using` declaration.
- Fixed #11017: `noUselessUndefined` no longer reports `return undefined` when the enclosing function has a return type annotation other than `undefined` or `void`.
- Fixed #11228: CSS block comments between a declaration colon and value now preserve their source indentation.

## Upgrade Command
```bash
npm install --save-dev --save-exact @biomejs/biome@2.5.8
```