Contributing build signatures

The signature database is this project’s collective memory of React Native build failures. Every signature you add means an agent somewhere skips the hour you just lost.

The contract

A signature is an entry in signatures/{ios,android,cocoapods,metro}.yaml:

- id: android-my-new-failure          # kebab-case, platform-prefixed, unique
  title: Short human title
  platform: android                   # ios | android | cocoapods | metro
  match:
    - 'a JS regex tested against each log line'
  errorType: dependency               # dependency | compile | link | codegen | config | environment | cache
  probableCause: >-
    Why this happens, in one or two sentences.
  suggestedFix: >-
    What fixes it. Mention server tools when relevant (e.g. run_pod_install).
  fixtures:
    - android/my-new-failure.log      # REQUIRED — at least one

Plus the matching evidence: a real log excerpt (10–30 lines around the error) at test/fixtures/build-logs/android/my-new-failure.log.

What CI enforces

The test suite is generated from the YAML, so your PR is verified automatically:

1. Your fixture must match your signature.
2. Your regex must not match any log in the clean corpus (test/fixtures/build-logs/clean/ — successful builds).
3. Ids are unique; patterns are bounded (≤400 chars); cause and fix are non-trivial.

Run it locally with pnpm test.

Tips for good signatures

• Capture file/line with named groups when the error line carries them: '(?<file>[^\s:]+):(?<line>\d+): error: …'.
• Match the stable part of the message; version numbers and paths change — prefer [\d.]+ and \S+ over literals.
• suggestedFix should be executable advice, not “investigate the error”.

Can’t open a PR? Use the signature issue form and a maintainer will convert it.