| name | docs-eas-env-drift |
| version | 0.1.0 |
| description | Audit the "Built-in environment variables" list on the Expo docs EAS environment-variables usage page against the env definition sites in expo/eas-cli (report only, never edits docs). Use when the user asks whether the built-in EAS Build env vars are outdated, says "eas env drift", "check built-in env vars", or "/docs-eas-env-drift". |
| argument-hint | ["path-to-expo-docs-checkout"] |
| allowed-tools | Read, Grep, Write, Bash(bun:*), Bash(git:*) |
docs-eas-env-drift
The docs page pages/eas/environment-variables/usage.mdx lists the env vars EAS Build injects into every job. The truth is two files on expo/eas-cli@main: literal setEnv() calls in packages/worker/src/env.ts (cloud builds) and the env object in packages/local-build-plugin/src/build.ts (local builds). Manual sync has already failed twice: the files' own "keep in sync" comments point at the retired turtle-v2 repo, and the packages moved repos once (eas-build was archived into eas-cli), so the script fails loudly rather than reporting a clean run when a truth file vanishes. The deliverable is a local markdown report; this skill detects drift, it never edits docs.
The audited contract is EAS_BUILD* plus CI. Other vars the runners set (GRADLE_OPTS, LANG, MAESTRO_*) are infra tuning, out of scope by design.
Inputs
$ARGUMENTS is an optional path to a local expo/docs checkout. Default: ~/Documents/GitHub/expo/docs. If neither resolves, ask the user.
When NOT to use
- Env vars of other EAS surfaces (Workflows, Hosting). Different runners, different docs pages.
- Editing the docs page. Findings go in the report; a human applies them.
- Offline. The truth files are fetched from
raw.githubusercontent.com.
Requirements
bun, network access to raw.githubusercontent.com, a local expo/docs checkout.
Step 1: Extract
bun <skill-dir>/scripts/extract.ts $ARGUMENTS
| Line | Meaning | Your action |
|---|
FATAL <why> | Truth file unreachable or page restructured | Stop. Locate the new definition site or collapsible first; never report a clean run. |
UNDOCUMENTED <var> <runners> | Set by those runners, missing from the docs list | Finding. Check it isn't documented elsewhere (step 2). |
STALE <var> | Documented, set by no runner | Finding: removal candidate. |
CLOUD_ONLY <var> / LOCAL_ONLY <var> | Documented, but only one runner sets it | Finding: the list needs a per-runner caveat. |
VALUE_MISMATCH <var> docs=<v> <runner>=<v> | Docs claim a literal value a runner contradicts | Finding. |
EXPECTED <var> <reason> | Known intentional asymmetry | List under "known", no action. |
COUNTS docs=N cloud=N local=N | Inventory sizes | Header sanity check; a sudden drop means extraction broke. |
For each UNDOCUMENTED var, check whether another page already covers it:
grep -rn "<var>" <docs-repo>/pages --include='*.mdx'
A hit outside usage.mdx downgrades the finding to "documented elsewhere, consider cross-linking"; no hits anywhere means it is fully undocumented.
Step 2: Report
Write docs-eas-env-drift-<YYYY-MM-DD>.md in the current working directory:
- Header: date, docs commit (
git -C <docs-repo> rev-parse --short HEAD), the two truth file paths on expo/eas-cli@main, and the COUNTS line.
- Findings: grouped by category, one plain sentence each, with the
usage.mdx line number for vars already in the list (grep the collapsible) and the grep result for undocumented ones.
- Known asymmetries: the
EXPECTED lines, so readers don't re-report them.
Plain statements only, no rewritten doc text. The report is the only write; whether and how to fix the docs is the writer's call.
