Next.js plugin not detected using ESLint v9

[RobertFent]

Summary

During next build I get this warning:
The Next.js plugin was not detected in your ESLint configuration. See https://nextjs.org/docs/app/api-reference/config/eslint#migrating-existing-config

I followed the steps described there but could not figure out how to fix this.

Here is my current eslint.config.mjs:

import { defineConfig, globalIgnores } from 'eslint/config';
import typescriptEslint from '@typescript-eslint/eslint-plugin';
import pluginNext from '@next/eslint-plugin-next';
import prettier from 'eslint-plugin-prettier';
import pluginCypress from 'eslint-plugin-cypress';
import tsParser from '@typescript-eslint/parser';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import js from '@eslint/js';
import { FlatCompat } from '@eslint/eslintrc';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const compat = new FlatCompat({
	baseDirectory: __dirname,
	recommendedConfig: js.configs.recommended,
	allConfig: js.configs.all
});

export default defineConfig([
	globalIgnores([
		'**/node_modules',
		'**/.next',
		'**/*.config.*',
		'**/*.js',
		'**/next-env.d.ts'
	]),
	{
		extends: compat.extends(
			'next',
			'eslint:recommended',
			'plugin:prettier/recommended',
			'plugin:@typescript-eslint/eslint-recommended',
			'plugin:@typescript-eslint/strict',
			'plugin:@typescript-eslint/stylistic',
			'prettier',
			'plugin:@next/next/recommended' // todo: The Next.js plugin was not detected in your ESLint configuration. See https://nextjs.org/docs/app/api-reference/config/eslint#migrating-existing-config
		),

		plugins: {
			'@typescript-eslint': typescriptEslint,
			'@next/next': pluginNext,
			prettier,
			cypress: pluginCypress
		},

		languageOptions: {
			parser: tsParser
		},
			...pluginNext.configs.recommended.rules
		}
	}
]);

All the other plugins are working like a charm. Anybody had the same problem?

[Acervans]

I had the same problem, it's because you're ignoring eslint.config.mjs with the rule '**/*.config.*', so next can't read it.

[RobertFent]

This did the trick. Thank you so much!😁