ethanblauw-hub · Nov 2, 2026 · Nov 2, 2026 · Nov 2, 2026
diff --git a/docs/backlog.md b/docs/backlog.md
@@ -103,6 +103,8 @@ Sequencing and dependency order live in [`roadmap.md`](./roadmap.md), not here.
 | [B-067](#b-067) | Nothing records which tools are called, so usage can only be surveyed from agents' memory | cross-session survey, 2026-11-02 | S | raw |
 | [B-068](#b-068) | A git-mode index on an alias ref goes stale without warning when the alias's branch is retired | cross-session survey, 2026-11-02 | S | raw |
 | [B-069](#b-069) | `trace_data_flow` can't see writes made through a project's own helper; no way to add rules in `indexer.toml` | ADR-053 open question 3, 2026-11-02 | S | raw |
+| [B-070](#b-070) | In git mode, `reindex()` warns the index is stale and advises a full rebuild, because it compares against the checkout's `HEAD` instead of the indexed ref | live passes on V2 and Gantt, 2026-11-02 | S | raw |
+| [B-071](#b-071) | Docs-only merges to master still run the full CI and the 19-minute retrieval tripwire | @edb via conductor, from InventoryApp-V2's CI, 2026-11-02 | S | raw |
 
 > **Not tracked here:** open work that a built ADR already owns. ADR-025's GPU-blocked end-to-end
 > reindex, ADR-011's Stage 2b member chains, ADR-006's Leiden backend and ADR-008's confidence-curve
@@ -2296,3 +2298,91 @@ shape (`definition`, `producer`, `file_marker`, with `{name}` for the traced nam
 @edb chose not to build it inside ADR-053.
 
 **Related:** ADR-053 §2, ADR-026 (configuration authority).
+
+### B-070 — In git mode, `reindex()` reports a false staleness warning and advises a full rebuild
+
+**Source:** the first live passes on the post-ADR-055 code, InventoryApp-V2 and GanttWebApp,
+2026-11-02 · **Status:** raw · **Size:** S
+
+`_reindex()` in `src/MCPServer.py` builds its "INDEX STALENESS DETECTED" block by comparing
+`last_indexed_commit` with `git rev-parse HEAD` and listing `git diff --name-only <last> HEAD`. It
+never checks the index's source. In git mode the index follows a ref, not the folder's checkout, and
+both live repos keep their main folder on a feature branch:
+
+- **InventoryApp-V2:** the folder is on `fix/closed-jobs-sync` and the index follows `origin/main`. The
+  warning listed about 600 files.
+- **GanttWebApp:** the folder is on `feat/ic-generalization` and the index follows
+  `refs/code-index/target`. The warning listed about 330 files, then the same result said
+  "Nothing changed — index is up to date", because the index really was current on e8fd91e.
+
+Both warnings end with "Consider reindex(changed_files_only=False) for a clean rebuild". That is a
+full wipe and re-embed, advised for no reason. Both sessions saw the contradiction and didn't run it,
+but an agent that trusts the advice would pay a full rebuild every time it reindexes from a branch.
+`index_status` already gets this right: it compares against `ref or "HEAD"` and reports
+"your HEAD vs index" separately.
+
+**Want:**
+1. In git mode, compare against the source ref, using the same `git_ref()` that `index_status`
+   uses. If the index is current on it, print no warning. Keep the plain `HEAD` check for folder mode.
+2. Drop the "Consider reindex(changed_files_only=False)" line in both modes. Since ADR-049, the
+   incremental pass already re-checks every file's content, so a full rebuild doesn't fix what the
+   warning describes.
+3. **Same root, smaller:** `_server_instructions()` quotes `commit …, last verified …` as it was when
+   the client connected, and Claude Code doesn't refresh instructions mid-session. Gantt's session
+   saw 86d34d5 in its instructions while `index_status` said e8fd91e. Name the source there and point
+   to `index_status` for the live commit, instead of quoting one that goes stale.
+
+**Done when:** a regression test runs `_reindex()` against a git-mode index whose folder `HEAD` is
+on another branch and gets no staleness block, and a folder-mode test still gets one.
+
+**Related:** ADR-042 (git-mode source), ADR-049 (incremental default), [B-066](#b-066), [B-068](#b-068).
+
+### B-071 — Docs-only merges to master still run the full CI and the 19-minute retrieval tripwire
+
+**Source:** @edb, via the conductor session, 2026-11-02. The reference is InventoryApp-V2's
+`.github/workflows/ci.yml` (#294, #304, #405). · **Status:** raw · **Size:** S
+
+`ci.yml` runs all five jobs on every PR and push, docs included. `tripwire.yml` filters PRs by path,
+but runs on every push to master, so a docs-only merge also pays the tripwire. Measured from
+`gh run list` on 2026-11-02:
+
+| Run | Wall time |
+|---|---|
+| `CI` on a docs-only PR (#93, #96) | about 4 min |
+| `CI` on a push to master | 3–7 min |
+| `Retrieval tripwire` on a push to master | 11–20 min |
+
+Two of the last ten master pushes were docs only, #87 and #93, and each ran the tripwire for about
+18 minutes.
+
+**What changes the picture:** the repo is **public**, so GitHub-hosted runners cost nothing here.
+V2's per-minute billing reasons don't apply. The gain is time and runner noise, not money. There's
+also no branch protection on master, so no required check would wait on a skipped workflow.
+
+**V2's six techniques, and how each fits here:**
+1. **Skip docs-only changes: yes.** Without required checks, plain `paths-ignore`
+   (`docs/**`, `.claude/**`, `**.md`) on both workflows' `push` and `pull_request` triggers is
+   enough. V2 uses a first step instead because it has required checks. If master gets branch
+   protection later, switch to that.
+2. **Fail open: built in.** `paths-ignore` runs the workflow as soon as any changed file isn't docs,
+   and GitHub runs it anyway when the diff is too large to filter. V2's "previous run failed" guard
+   protects against cancelled master runs. Master runs are never cancelled here, so it isn't needed.
+3. **Expensive suite opt-in by label: not needed.** The tripwire is already path-filtered on PRs and
+   can be run by hand with `workflow_dispatch`.
+4. **Concurrency: keep as is.** PRs already cancel superseded runs. Master gets a full run per
+   merge on purpose (the comment in `ci.yml`), so a burst of merges still tests each commit.
+5. **One job instead of five: no.** Rounding each job up to a whole minute costs nothing on a public
+   repo, and five parallel jobs finish sooner than one serial job.
+6. **Reuse the PR's run on master's same tree: no.** Merges here usually land one after another, so
+   master's tree rarely matches the PR's tested tree, and the reuse would almost never apply.
+
+**Want:** item 1 only. Add `paths-ignore` to both workflows, and keep the tripwire's existing PR
+`paths` list. `paths` and `paths-ignore` can't both be set on the same trigger, so `push` gets
+`paths-ignore` and `pull_request` keeps `paths`.
+
+**Done when:** a docs-only PR and its merge start no `CI` and no `Retrieval tripwire` run, and a
+one-line change under `src/` still starts both.
+
+**Watch for:** a `.md` file that a CI check reads would be skipped too. As of 2026-11-02, nothing
+CI runs reads one. `tools/conformance_eval.py` touches `README.md` only under `--write-readme`,
+which CI doesn't run, and `tools/gen_pr_body.py` isn't in CI. Check again when adding a check.