Environment

Node version: v20.19.1
npm version: v10.8.2
Local ESLint version: v9.26.0 (Currently used)
Global ESLint version: Not found
Operating System: darwin 24.4.0

What parser are you using?

Default (Espree)

What did you do?

await eslint.lintText(text, {
  filePath,
  warnIgnored: true,
})

What did you expect to happen?

No error without delete eslintConfig.overrideConfig.plugins;

What actually happened?

ConfigError: Config (unnamed): Key "plugins": Cannot redefine plugin "@".

Link to Minimal Reproducible Example

prettier/prettier-eslint#1190

Reproduce steps:

yarn install
# remove `delete eslintConfig.overrideConfig.plugins;` at src/index.ts#L250
yarn format

Participation

• I am willing to submit a pull request for this issue.

Additional comments

I'm adding eslint v9 support for https://github.com/prettier/prettier-eslint at prettier/prettier-eslint#1190