buildGbrainEnv leaves PGLite users exposed to .env poisoning → broken-db false-positive

[techguyisme2]

buildGbrainEnv leaves PGLite users exposed to .env poisoning → broken-db false-positive

Summary

PR #1583 (CHANGELOG line 1359, 1410) fixed lib/gbrain-local-status.ts:freshClassify so the probe's env is routed through buildGbrainEnv. The fix is complete for Postgres/Supabase brains but incomplete for PGLite brains, because buildGbrainEnv works by seeding DATABASE_URL from ~/.gbrain/config.json — and a PGLite config has no database_url field.

For PGLite users, line 111 of lib/gbrain-exec.ts fires if (!cfg.database_url) return out; and returns the caller env unmodified. Bun's auto-load of the cwd's .env then flows straight through to the gbrain sources list --json probe, gbrain treats the leaked DATABASE_URL as a Postgres override, connection fails, classifier reads "Cannot connect to database" from stderr, and returns broken-db. The 60s cache then propagates that poisoned negative to clean directories.

Net effect: every PGLite user with a DATABASE_URL in any project's .env (sqlite, mysql, app DB on a different port, etc.) sees broken-db from gstack — and brain-aware blocks get silently suppressed in their planning-skill SKILL.md files.

Reproduction

Setup: gbrain 0.42.x with engine: "pglite" (e.g. ~/.gbrain/config.json lacks database_url).

# Working: $HOME, no .env in scope, no DATABASE_URL leaked
rm -f ~/.gstack/.gbrain-local-status-cache.json
( cd "$HOME" && env -u DATABASE_URL -u GBRAIN_DATABASE_URL \
    ~/.claude/skills/gstack/bin/gstack-gbrain-detect ) | jq .gbrain_local_status
# → "ok"

# Broken: any project repo with DATABASE_URL in .env
cd /path/to/some-project   # contains .env with DATABASE_URL=sqlite:///app.db
rm -f ~/.gstack/.gbrain-local-status-cache.json
~/.claude/skills/gstack/bin/gstack-gbrain-detect | jq .gbrain_local_status
# → "broken-db"

# Direct gbrain works fine — proving the brain isn't actually broken:
gbrain sources list --json   # exit 0, valid JSON, empty stderr

The broken-db classification then gets cached for 60s and propagates to subsequent probes even from clean directories.

Why PR #1583 didn't cover this

buildGbrainEnv in lib/gbrain-exec.ts:95-127 is built around seeding DATABASE_URL:

export function buildGbrainEnv(opts: BuildGbrainEnvOptions = {}): NodeJS.ProcessEnv {
  const baseEnv = opts.baseEnv || process.env;
  const out: NodeJS.ProcessEnv = { ...baseEnv };
  if (baseEnv.GSTACK_RESPECT_ENV_DATABASE_URL === "1") return out;
  ...
  if (!cfg.database_url) return out;          // ← PGLite escape hatch
  ...
  out.DATABASE_URL = cfg.database_url;
}

For PGLite (file-engine, no URL), cfg.database_url is undefined, line 111 returns out (which is { ...baseEnv }), and the .env-poisoned DATABASE_URL is preserved unchanged. The probe sees it, gbrain dutifully tries to connect to Postgres, fails, and the classifier locks in broken-db.

Suggested fix

When the resolved config engine is PGLite, strip DATABASE_URL / GBRAIN_DATABASE_URL from the returned env instead of passing through. The config schema already carries enough signal — either engine === "pglite" or database_path present with no database_url. Sketch:

// lib/gbrain-exec.ts
if (!cfg.database_url) {
  // PGLite engine has no DATABASE_URL to seed. Strip any caller-supplied
  // value (e.g. Bun-autoloaded project .env) so the file-backed brain
  // isn't probed as Postgres → "Cannot connect to database" → broken-db.
  if (cfg.engine === "pglite" || cfg.database_path) {
    delete out.DATABASE_URL;
    delete out.GBRAIN_DATABASE_URL;
  }
  return out;
}

GSTACK_RESPECT_ENV_DATABASE_URL=1 keeps its escape hatch (handled before this branch).

Same one-liner pattern should probably be mirrored in lib/gbrain-local-status.ts:223-265 freshClassify if buildGbrainEnv shouldn't take on the engine-aware behavior directly.

Test coverage to add

A freshClassify test case with:

• ~/.gbrain/config.json set to {"engine":"pglite","database_path":"..."} (no database_url)
• caller env supplies DATABASE_URL=sqlite:///x.db (simulating the Bun .env autoload)
• stub gbrain exits 0 with valid JSON when called with no DATABASE_URL env
• assert localEngineStatus() returns "ok", not "broken-db"

This would have caught the regression and would prevent it from re-emerging.

Environment

• gstack: 1.57.6.0 (current main tip, commit 9cc41b7)
• gbrain: 0.42.29.0
• Engine: PGLite (~/.gbrain/config.json has engine: "pglite", database_path: ..., no database_url)
• Host: macOS / zsh
• Triggering .env (in an unrelated project repo, cwd at probe time): DATABASE_URL=sqlite:///node0.db

References

• PR fix(gbrain-local-status): classifier falsely reports broken-db inside repos with their own DATABASE_URL #1583 — original freshClassify fix (Postgres/Supabase complete, PGLite incomplete)
• CHANGELOG.md lines 1359, 1410 — describes the symptom this issue extends
• lib/gbrain-exec.ts:95-127 — buildGbrainEnv definition
• lib/gbrain-local-status.ts:223-265 — freshClassify (the probe call site)