Vercel build logs or terminal

Failed to compile. Error: '…' is defined but never used. (@typescript-eslint/no-unused-vars)

What it means
The code quality check (ESLint) stopped the build because a leftover variable or import isn't used anywhere.
Likely causes
  • An import or helper variable was left behind after refactoring a component.
  • npm run lint wasn't run before pushing to GitHub.
Prevention
Run npm run lint before every commit and push.

Copy for your agent

The build failed on an ESLint error. Run `npm run lint`, clean up the unused imports or variables, verify `npm run build` passes locally, and push.

Full help articleThe Vercel build failed

Last reviewed Nov 8, 2026