neohaskell/docs/archive/2026-07-ai-artifacts/claude-skills/feature-pipeline-preview/15-final-verify/03-hlint

ARCHIVAL KNOWLEDGE — DO NOT USE OR REFERENCE. Superseded by codemap/ + root AGENTS.md. Scheduled for deletion once the pipeline is verified (Phase 6). Manifest: docs/archive/2026-07-ai-artifacts/MANIFEST.md

name: 03-hlint description: Runs hlint as a final pass that captures warnings for the PR body without gating the pipeline. kind: leaf executor: script model: claude-haiku-4-5-20251001

Final Hlint

Runs hlint against the changed Haskell files one last time and writes the output to .pipeline/hlint.log. Hlint warnings are collected, not gated — this leaf does not fail the final-verify phase on warnings. The PR-body step in phase 16 surfaces the log contents to the PR reviewer.

Inputs

• The changed Haskell file list from a merge-base diff: BASE=$(git merge-base HEAD origin/main 2>/dev/null || git merge-base HEAD main) && git diff --name-only "$BASE"...HEAD -- '*.hs' '*.lhs'. Three-dot range so committed branch deltas show up in CI; pathspec so an empty match stays exit-0.

Plan

1. Compute the changed Haskell files list → verify: list captured.
2. Run hlint on the list, redirecting stdout+stderr to .pipeline/hlint.log (overwriting any earlier build-loop log so the final state is canonical) → verify: log written.
3. Always exit 0 — the leaf records warnings, the PR body surfaces them, and CI's own hlint check is the canonical gate at merge time. When hlint is unavailable, write a placeholder line (hlint: missing) to .pipeline/hlint.log and still exit 0 so the phase-complete check (.pipeline/hlint.log refreshed) has a single canonical signal → verify: caller sees exit 0, .pipeline/hlint.log always exists.

Assumptions:

• Phase 15's earlier steps (01-build, 02-test) are the strict gates here; hlint is informational for the PR reviewer.
• .pipeline/hlint.log is canonical at PR-body time — it reflects the final state after fix-findings (phase 14).

If any assumption fails, refuse — do not guess.

Steps

1. Compute changed files against the PR merge-base so CI (where everything is committed) sees the same delta as a local checkout: BASE=$(git merge-base HEAD origin/main 2>/dev/null || git merge-base HEAD main); git diff --name-only "$BASE"...HEAD -- '*.hs' '*.lhs'.
2. If the list is empty, write an empty .pipeline/hlint.log and exit 0.
3. Otherwise run: nix develop --command hlint <files...> > .pipeline/hlint.log 2>&1 || true — the trailing || true keeps the leaf at exit 0 regardless of warning count.
4. If the log is non-empty, print a one-line summary to stdout (hlint produced N warning(s); see .pipeline/hlint.log and the PR body). Do not surface as failure.
5. Exit 0.

Output

.pipeline/hlint.log written (possibly empty), reflecting the final-verify pass. Exit code is always 0 unless a hard environmental failure occurred.

Refusals

• Repo not a git working tree → refuse: "not in a git repo" and exit non-zero. Without a git tree we cannot compute the changed-file list at all.

Note: nix or hlint missing is not a refusal here. Write hlint: missing to .pipeline/hlint.log and exit 0 — phase-complete only cares that the log was refreshed.