I tried all the suggestions above (fixing warnings, CI= npm…) when i build it locally it build successfully,
i tried changing to yarn command, i tried deleting json-lock like warning suggested.
Build failed due to a user error: Build script returned non-zero exit code: 2 8:40:17 PM: > firstname.lastname@example.org build /opt/build/repo/client 8:40:17 PM: > react-scripts build 8:40:17 PM: sh: 1: react-scripts: not found 8:40:17 PM: npm ERR! code ELIFECYCLE 8:40:17 PM: npm ERR! syscall spawn 8:40:17 PM: npm ERR! file sh 8:40:17 PM: npm ERR! errno ENOENT 8:40:17 PM: npm ERR! email@example.com build: `react-scripts build` 8:40:17 PM: npm ERR! spawn ENOENT
git repo: https://github.com/1LifeLess/Ebay-Netlify_react_express
Netlify deploy path: https://app.netlify.com/sites/ebayapi/deploys/5fdf9d2eab133dc73b39ded0
full log: /opt/buildhome/.npm/_logs/2020-12-20T18_52_01_586Z-debug.log