hooks: resolve repo root from the invoking worktree, fail closed - #92

Summary

Fixes a wrong-tree bug in the local git-hook gates: .githooks/pre-commit and .githooks/pre-push resolved the repository root from the hook file's own location (SCRIPT_DIR/..). Because core.hooksPath is an absolute path into the primary checkout, any commit or push from a linked session worktree was validated (consistency check, test gate, compliance chain entry) against the primary checkout's tree — stale or dirty with another session's edits — instead of the tree actually being committed. Observed 2026-08-05 as a false NOTICE ... drifted pre-commit FAIL from a worktree whose own tree passed; the same shape can produce false PASSes.

Both wrappers now resolve REPO_ROOT="$(git rev-parse --show-toplevel)" and fail closed when the root cannot be resolved (no cwd fallback — per the Codex cross-family review, a fallback would re-open the exact wrong-tree class this fixes). The pre-push test-gate subshell sanitization and the exec'd compliance checker (hook env + stdin preserved) are structurally unchanged.

Operational note: the fix becomes ACTIVE only when the primary checkout — whose working tree hosts the core.hooksPath copies — is updated to a commit containing it (currently parked on a stale commit with uncommitted edits from another session; not touched by this PR).

Boundary declaration

• No provider executor source, raw provider command, credential, private absolute path, retired package tree, downloader, or post-install hook is included.
• Native-runtime changes, if any, contain only a final signed artifact and reviewed public verification metadata; implementation and credentials remain private. (No native-runtime changes.)
• The change does not create a host-specific preset or provider-specific plugin.

Generated and release surfaces

• Skill specs and generated SKILL.md files are in parity. (build_skills.py --check OK — untouched.)
• Claude and Codex marketplaces/manifests are in parity. (build_marketplace.py --check OK — untouched.)
• A unique changelog.d/ fragment is present for a user-visible change (changelog.d/20260805-hook-worktree-root.md); generated CHANGELOG.md untouched.
• Version metadata is bumped when behavior or distributed content changes. (N/A — repository tooling only, no distributed content; no bump, per the .githooks pre-push wrapper precedent.)

Verification

• python3 scripts/build_skills.py --check — OK
• python3 scripts/build_marketplace.py --check — OK
• python3 scripts/build-changelog.py --dry-run — OK (--check is release-PR-only under the fragment-only convention)
• python3 -m unittest discover -s tests -t . -v — Ran 660, OK
• python3 -m unittest discover -s scripts -p 'test_*.py' -v — Ran 333, OK (327 + 6 new: hook-lives-elsewhere for both wrappers, fail-closed rev-parse for both, branch-detection knob split, real-git linked-worktree integration test)
• python3 scripts/check_release_consistency.py — RESULT: OK (in the PR worktree)
• python3 scripts/secret_scan.py — clean
• python3 scripts/check-public-export-safety.py --active-tree — SAFE (history mode not run: local clone retains pre-rewrite lineage and fails history mode by design; see docs/public-governance.md. No history modified.)
• git diff --check — clean
• Live end-to-end: the new pre-commit run from the previously-failing session worktree validates THAT worktree and passes (the old hook produced the false NOTICE FAIL from the same invocation).

Commit made with --no-verify for documented cause: the currently-ACTIVE pre-commit is the primary checkout's pre-fix copy exhibiting exactly the bug this PR fixes; every gate it would run is green in this tree (above) and re-runs authoritatively in CI.

Review and post-condition

Tier 2 (repository validation tooling). Independent cross-family review: Codex (OpenAI, gpt-5.5, effort high, CLI read-only sandbox) — initial verdict DISAGREE-MINOR (confidence H): core root-resolution change endorsed ("the hook file path is irrelevant to Git's repository discovery"); load-bearing recommendation to replace the cwd fallback with fail-closed — integrated (both hooks now hard-fail, with tests). Suggested real-git worktree integration test — integrated. Suggested re-cd'ing the exec'd compliance checker under sanitized env — declined with cause: hook-pre-push.py requires the hook's git env and stdin ref data, and resolves its own root from __file__. Post-merge: update the primary checkout so the fixed hooks become active, then a worktree commit exercises the fix in production.

Compliance trace

author: Claude (Anthropic) on behalf of @sumitake
standing_directives: AGENTS.md source boundaries; docs/public-governance.md; adversarial review folded into cross-check per operator directive
tier: 2
cross_check: PROCEED-WITH-MODIFICATIONS — Codex (OpenAI, gpt-5.5) DISAGREE-MINOR/H; fail-closed root resolution and real-git integration test integrated; compliance-checker re-cd suggestion declined with cause (needs hook env + stdin)
post_condition: CI green; primary checkout to be updated so fixed hooks activate; worktree commit then validates its own tree
mcp_coverage_gap: NONE — no MCP tool surface changes
contributor_rights: OWNER-AUTHORED
operator_reserved: no

🤖 Generated with Claude Code