Yarn lockfile out of date

April 30, 2026 · View on GitHub

Playbook ID: yarn-lockfile Category: build Severity: medium Tags: yarn, node, lockfile, dependencies

What this failure means

Yarn was run with --frozen-lockfile (the recommended CI flag) but the yarn.lock file is either missing or no longer matches package.json.

Common log signals

your lockfile needs to be updated
yarn.lock: No such file or directory
error your lockfile needs to be updated
YN0028
The lockfile would have been modified by this install
lockfile is frozen

Diagnosis

Yarn was run with --frozen-lockfile (the recommended CI flag) but the yarn.lock file is either missing or no longer matches package.json.

Fix steps

  1. Run yarn install locally.
  2. Commit the updated yarn.lock.
  3. Ensure yarn.lock is not in .gitignore.
  4. If the repository uses Yarn workspaces, regenerate the lockfile from the workspace root with the same Yarn version used in CI.

Validation

  • Re-run the failing workflow step.
  • Confirm the original failure signature for Yarn lockfile out of date is gone.

Likely files to inspect

(Not specified.)

Run Faultline

faultline analyze build.log
faultline explain yarn-lockfile
faultline workflow build.log --json --mode agent

Search phrases this page answers

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Generated from playbooks/bundled/log/build/yarn-lockfile.yaml. Do not edit directly — run make docs-generate.