# EAS build fails at Install dependencies: Missing package from lock file

> EAS build images run npm 10, but the lockfile was written by npm 11. npm 11 leaves out some nested entries for optional or conflicting peers (here a nested peer of a chat SDK needing flash-list >=2.1.0) that npm 10's npm ci insists on.

Web page: https://davidewins.com/errors/eas-npm-ci-missing-from-lock-file

npm. Confirmed fix, 11 September 2026.

Versions: EAS builders npm 10.9.8 / Node 22; local npm 11 / Node 25; Expo SDK 57 (expo ~57.0.20, React Native 0.86.3, React 19.2.3)

Error:

```
npm error `npm ci` can only install packages when your package.json and package-lock.json are in sync. Missing: @shopify/flash-list@2.3.2 from lock file
```

## Cause

EAS build images run npm 10, but the lockfile was written by npm 11. npm 11 leaves out some nested entries for optional or conflicting peers (here a nested peer of a chat SDK needing flash-list >=2.1.0) that npm 10's `npm ci` insists on. Local `npm ci` passes, EAS fails, and the EAS summary only says "Unknown error".

## Fix

1. Reproduce locally with the builder's npm:
```bash
npx -y npm@10.9.8 ci --include=dev --dry-run
```
2. Add the missing entries without changing versions:
```bash
npx -y npm@10.9.8 install --package-lock-only
```
3. Re-run the dry run, commit the lockfile, then queue the build. Repeat after every `npx expo install`, because it runs your local npm 11 again.

## More npm errors

- [EAS Install dependencies fails after adding a video SDK: deduped package below its peer range](https://davidewins.com/errors/eas-npm-ci-nested-peer-url-polyfill)
- [`npm ci | tail` reports exit 0 but the build still fails on install](https://davidewins.com/errors/pipe-exit-code-hides-npm-ci-failure)
- [`npx -y typescript@x tsc --noEmit` prints no TS errors but did not typecheck at all](https://davidewins.com/errors/npx-typescript-could-not-determine-executable)

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