Slice Land

Spec 007 created this skill from scratch. The deterministic readiness checks + report generation live in land.py; this SKILL.md drives the judgment layer (when to invoke, how to interpret blockers, what mode to pick).

What this skill does

Closes the worktree-drift gap: every slice in jig today commits to a worktree branch and stays there until a human remembers to merge. The skill provides a deterministic landing path:

• Verify the slice is actually done — STATUS=DONE in spec.md, full test suite green, deviation log section present, DoD checkboxes all ticked.
• Emit a structured markdown report with five readiness checks (STATUS=DONE, tests green, deviation log present, DoD ticked, and the Class-A cross-ref backstop — spec 112: refuse when the slice/ADR is already integrated on origin/main, JIG_CROSSREF_GATE=0 to bypass) and (in --mode direct or --mode pr) a Next-steps section of suggested git commands.

prepare is non-destructive on git state: it may read branch state and fetch origin/main to surface a branch-freshness warning, but it never switches branches, merges, pushes, or removes worktrees. execute --mode direct runs the destructive merge sequence by pushing the current branch to origin/main, then fast-forwards the canonical local main worktree to origin/main or reports why local sync was skipped (slice 007-02 + 081-01); execute --mode pr runs the destructive push + PR-open sequence (slice 007-03). git worktree remove and gh pr merge are never executed — both stay user-driven post-landing suggestions.

How to use

Run the readiness check

python3 "${CLAUDE_PLUGIN_ROOT}/skills/slice-land/land.py" prepare \
  <path-to-spec.md> <slice-fragment> [--mode {direct,pr}]

• spec.md — path to the spec file (e.g. docs/specs/007-slice-land/spec.md).
• <slice-fragment> — case-insensitive substring against ## Slice X — Y headings. Same lenient match as workflow.py transition.
• --mode — optional. Without it, only the readiness check runs.
  • direct — for solo / merge-to-main projects. Suggested commands: push the branch to origin/main, then fast-forward local main to origin/main when a clean canonical main worktree exists.
  • pr — for team / PR-shaped flows. Suggested commands: git push -u origin <branch> && gh pr create --body-file <path>. A PR body is written to /tmp/jig-slice-<NNN-NN>-pr-body.md containing the slice's ACs and a deviation-log excerpt.

Run the merge sequence (execute --mode direct)

After prepare confirms the slice is ready, execute --mode direct runs the direct landing sequence:

python3 "${CLAUDE_PLUGIN_ROOT}/skills/slice-land/land.py" execute \
  --mode direct <path-to-spec.md> <slice-fragment> [--dry-run]

• --dry-run — print the git commands that would run without executing them. Use this for a final sanity check before committing.
• Without --dry-run — runs git push origin <branch>:main from the current worktree after the fast-forward guard passes, then fetches and fast-forwards the canonical local worktree checked out at refs/heads/main to origin/main when that worktree exists and is clean. The caller's feature/detached worktree is not switched to main. Stops and reports if the authoritative push fails. If the post-push local sync cannot run because main is missing, dirty, locked, diverged, or unavailable, the report says local main sync skipped: <reason> while preserving the successful authoritative push. Never runs git worktree remove (printed as a post-landing suggestion only).

Safety guards (checked before any git mutation):

• Refuses if current branch is main or master.
• Refuses if main has diverged (fast-forward not possible).

Open the PR (execute --mode pr)

For PR-shaped flows, execute --mode pr pushes the branch and opens the PR via the GitHub CLI:

python3 "${CLAUDE_PLUGIN_ROOT}/skills/slice-land/land.py" execute \
  --mode pr <path-to-spec.md> <slice-fragment> [--dry-run]

• --dry-run — print the commands that would run, write the PR body file for inspection, but do NOT push or open the PR.
• Without --dry-run — runs git push -u origin <branch> followed by gh pr create --title "<title>" --body-file <body-path>. Stops if push fails (gh is NOT called after push failure). Title shape is feat(<scope>): <subject>: scope comes from a single skill: frontmatter value or falls back to the spec directory slug, and subject drops the numeric slice prefix so the PR-title workflow accepts it.
• Push runs from the current worktree (not the main worktree root, since the feature branch is checked out here).
• Never runs gh pr merge (printed as a post-landing suggestion only).
• Local main sync is pending until the PR actually merges. PR mode never claims local main was updated before origin/main moves.

Safety guards (checked before any subprocess mutation):

• Refuses if current branch is main or master.
• Refuses if gh CLI is not on PATH (install instructions printed).
• Refuses if origin does not point at github.com (HTTPS or SSH form).

Exit codes

• 0 — all five readiness checks pass; the slice is ready to land (for prepare) or was merged successfully (for execute).
• 1 — at least one check failed, a safety guard fired, or a git command failed (the report still emits; the user sees what's wrong).
• 2 — user error (missing spec, ambiguous fragment, invalid --mode).

Test-check warnings

If tdd.py run returns exit 2 (no test runner detected at the target), the readiness report marks the Tests row as a [?] warning rather than a [ ] blocker. Rationale: some slices are doc-only and have no executable tests — those slices should still be landable. Exit 1 from tdd.py run (red tests) IS a blocker.

Close-out (post-DONE) subsection

Slices often include items that can only be completed AFTER the RECONCILED → DONE transition — e.g. workflow.py status-board regen (which reads the updated STATUS marker) or CLAUDE.md skills-table promotion (which advertises the slice as done). These items create a chicken-and-egg if they live in the DoD: slice-land requires DoD = N/N before blessing landing, but the user uses slice-land's blessing as the cue to commit + flip to DONE.

Convention (spec 009 / slice 009-01): put post-DONE items in a subsection headed ### Close-out (post-DONE) inside the slice, after the DoD checklist and before the slice's --- separator. slice-land's check_dod recognizes the heading and excludes its checkboxes from the count. Anything between **DoD:** and ### Close-out is DoD-counted; anything after isn't.

Example:

## Slice 009-01 — close-out-section-recognition

**STATUS: DONE**

...

**DoD:**
- [x] All ACs pass; full suite green.
- [x] Reviewed by `reviewer` subagent.
- [x] Deviation log produced.
- [x] Reconciliation review pass.

### Close-out (post-DONE)

- [ ] `docs/specs/README.md` regenerated by `workflow.py status-board`
      AFTER the DONE transition.
- [ ] `CLAUDE.md` skills-table update.

The heading is case-insensitive (matches Close-out, Closeout, close out, etc.) and requires H3 (###) — H2/H4 don't delimit, to avoid accidentally matching unrelated content.

If no ### Close-out heading exists in the slice, check_dod behavior is unchanged (counts all boxes in the slice section).

When to invoke

Auto-trigger phrases: "land this slice", "merge back to main", "ready to ship", "create a PR for this slice", "close out the slice", "slice is done — what now".

Typical session flow:

1. Slice transitions to DONE via workflow.py transition.
2. Deviation log is written under the slice heading.
3. DoD checkboxes get ticked.
4. Run land.py prepare ... --mode direct (or --mode pr).
5. Copy-paste the suggested commands.

End-to-end example

# 1. Verify readiness — no merge command yet.
python3 .../land.py prepare docs/specs/007-slice-land/spec.md "007-01"

# 2. Get the direct-merge recipe.
python3 .../land.py prepare docs/specs/007-slice-land/spec.md "007-01" --mode direct

# Expected output (when all five checks pass):
#
#   # Landing readiness — slice 007-01 — land-prepare
#
#   ## Readiness checks
#
#   - [x] Status: DONE
#   - [x] Tests: green (`tdd.py run` exit 0)
#   - [x] Deviation log: present
#   - [x] DoD: 9/9 boxes ticked
#   - [x] Cross-ref state: not already integrated on origin/main
#
#   ## Next steps (mode: direct)
#
#   Run via `execute --mode direct` so `origin/main` is updated from
#   this branch, then the canonical local `main` worktree is
#   fast-forwarded as housekeeping when it is available and clean:
#
#       git push origin claude/eager-zhukovsky-34ebb0:main
#       git fetch origin main
#       git merge --ff-only origin/main
#       git worktree remove .claude/worktrees/eager-zhukovsky-34ebb0

Gotchas

• prepare is non-destructive; execute IS destructive. prepare only writes the PR body file (mode=pr); it never runs git checkout, git merge, git push, git worktree remove, or gh pr create. execute --mode direct runs the push/sync sequence as an authoritative push to origin/main and reports the post-push local sync result (007-02 / 081-01); execute --mode pr runs push + gh pr create (007-03) and reports local sync as pending on merge. Use --dry-run for a non-destructive preview of either execute mode.
• Test-check target = land.py's cwd. The helper invokes tdd.py run against the current working directory by default. If the slice changes a deep subdir (e.g. skills/foo/), run land.py from skills/foo/ (or pass it as cwd) to keep the test run focused. Running from the project root re-tests the whole suite — slower but also more honest.
• Substring fragment matching is identical to workflow.py. A fragment like 007-01 matches ## Slice 007-01 — land-prepare. Ambiguous fragments (multiple matches) refuse with exit 2.
• PR body file path is predictable (/tmp/jig-slice-NNN-NN-pr-body.md) so callers can read / edit the body before gh pr create. Re-running --mode pr overwrites the same file — idempotent.
• The Test plan section in the PR body uses generic [x] lines. The helper does not detect per-AC test counts — that would require the AC-coverage mapping deferred to slice 006-02. The generated checkboxes are placeholders; tighten the PR body manually before gh pr create if you want specific counts.
• Branch detection requires being inside a git repo. Outside one (e.g. running against a synthetic spec in /tmp), the helper degrades to the literal placeholder <BRANCH> in the suggested commands. Edit by hand before running.
• Deviation log detection is heading-based. The helper looks for ### Deviation log (or a variant like ### Deviation log (after reconciliation)) within the slice section. Missing heading → blocker, even if the slice has reconciliation content under another heading. Convention: every Done slice gets the explicit subsection.

Relationship to other skills

• spec-workflow owns the lifecycle state transitions (workflow.py transition). slice-land runs AFTER the final DONE transition; the two skills cleanly compose.
• independent-review runs BEFORE slice-land — review verdicts must be pass and reconciliation review must be done before the slice goes DONE. Once the slice is DONE, slice-land checks readiness and emits the landing recipe.
• tdd-loop is the helper slice-land shells out to for the test check. The test-check normalization (green / red / warn) maps directly to tdd.py run's exit code 0 / 1 / 2.
• adr-workflow is orthogonal — ADRs may or may not be written during reconciliation. slice-land doesn't gate on ADR presence.

Out of scope for slice 007-03

• scaffold.json integration: "direct" | "pr" field (slice 007-04 remains deferred — the --mode flag is sufficient for manual invocations).
• Multi-slice batch landing (single slice at a time is the right audit-trail granularity).
• Interactive confirm-before-push prompt — --dry-run is the preview mechanism instead. Use --dry-run, inspect the PR body, then re-run without --dry-run.
• JIRA / Linear ticketing integration, Slack notifications, auto-drafting ADRs from the deviation log.
• GitHub Enterprise (self-hosted) — the _check_github_remote substring match requires github.com literally. Self-hosted GHE users will need a future extension or local override.