CI "eslint: command not found" - Fix Missing ESLint Binary

The shell could not find an eslint executable. ESLint is not installed in the project, dev dependencies were pruned, or the step invoked a bare eslint that only resolves to a global install which CI does not have.

What this error means

The lint step fails with eslint: command not found (or not found) and exit code 127. The same command works locally where ESLint is on PATH or installed.

shell

$ eslint .
/bin/sh: 1: eslint: command not found
Error: Process completed with exit code 127.

Common causes

ESLint not installed or dev deps pruned

ESLint is missing from devDependencies, or the install ran with --omit=dev/--production, so the binary is absent in CI.

Calling a bare global eslint

The step runs eslint directly, relying on a global install. CI has no global ESLint, so it must use the local binary via npx/an npm script.

How to fix it

Install ESLint and call it locally

Add ESLint as a dev dependency and invoke the project-local binary.

Terminal

npm install -D eslint
# in CI, run via npm script or npx (resolves node_modules/.bin):
npx eslint .   # or: npm run lint

Keep dev dependencies for the lint step

Do not pass --omit=dev/--production to the install before linting.
Define a "lint": "eslint ." npm script so it resolves node_modules/.bin/eslint.
Use npm ci (with dev deps) so the binary is present.

How to prevent it

Declare ESLint in devDependencies and run it via an npm script or npx.
Keep dev dependencies installed for the lint step in CI.
Never rely on a global ESLint install in CI.