How to fix npm ERR! code ELIFECYCLE npm ERR! errno 127 in npm | DevErrors

How to fix "npm ERR! code ELIFECYCLE npm ERR! errno 127"

1Identify the missing command

Check what command failed:

bash

# See script content
cat package.json | jq '.scripts.build'

# If script is "webpack", check if installed
which webpack
ls node_modules/.bin/webpack

2Install missing dependency

Add the package:

bash

# Install locally (usually correct)
npm install webpack --save-dev

# Or globally if needed
npm install -g webpack

3Verify node_modules/.bin

Check bin directory exists:

bash

ls node_modules/.bin

# npm should automatically add this to PATH
# Verify with verbose output
npm run build --verbose

4Fix cross-platform scripts

Handle OS differences:

json

{
  "scripts": {
    "build": "webpack",
    "clean": "rimraf dist"
  }
}

Use cross-platform packages like rimraf, cross-env, shx.

5Use npx for one-off commands

Run without installing globally:

bash

npx webpack
npx jest

npx finds and runs the local or downloads temporarily.

6Reinstall dependencies

Clean install:

bash

rm -rf node_modules
npm install
npm run build

How to fix npm ERR! code ELIFECYCLE npm ERR! errno 127 in npm