bump-objectui.sh's walkability guard cannot detect a shallow objectui clone — the digest silently ships a complete-looking release record derived from a truncated history

[os-zhuang]

Found while correcting .changeset/console-82a94170c405.md (card #8893, PR #9398). Filing separately because the corrected table is one artifact, whereas this makes every console pin bump run in a shallow container ship the same fault.

The defect

scripts/bump-objectui.sh:139-142 decides whether the pin range can be walked:

RANGE_OK=0
if [[ "$OLD_SHA" != "(none sentinel)" ]] && git -C "$OBJECTUI_ROOT" cat-file -e "${OLD_SHA}^{commit}" 2>/dev/null; then
 RANGE_OK=1
fi

Its own comment names the case it means to catch — "(A shallow clone or a first-ever pin may not have OLD reachable — degrade to the tip subject, and SAY SO in the artifact: a degraded list and a complete one must never look alike, #4731.)" — but the implemented test only asks whether OLD_SHA exists as an object. It never asks whether the walk between the endpoints is complete.

In the common container shape the objectui clone is shallow and its graft boundary sits inside the pin range. Then:

1. cat-file -e OLD_SHA passes (the object is there), so RANGE_OK=1 and the degraded path at bump-objectui.sh:163 never fires.
2. collectAddedChangesets() runs git log --no-merges --diff-filter=A --name-only ... -- .changeset/, which walks only as far as the graft.
3. The graft boundary commit is parentless, so git diffs it against the empty tree and reports every .changeset/*.md in its tree as Added by it.
4. The seen dedup in collectAddedChangesets() hands it exactly the paths no newer commit claimed — a single "sink" commit absorbing a whole batch.
5. objectui-changeset-digest.mjs exits 0. Nothing in the artifact says the history was incomplete.

Measured, not inferred

The landed .changeset/console-82a94170c405.md credits 36 of its 119 entries to 183d09b78, a commit that adds exactly one changeset file. Reproduced exactly by grafting a full clone at that commit:

$ git rev-parse 183d09b78 > .git/shallow # synthesize the boundary
$ git rev-list --count --no-merges 665661ab0932..82a94170c405
110 # the landed record's denominator
$ git cat-file -e 665661ab0932^{commit} && echo PASSES
PASSES # so RANGE_OK=1, no degradation
$ node scripts/objectui-changeset-digest.mjs \
 --objectui-root GRAFTED_CLONE \
 --from 665661ab0932 --to 82a94170c405 --max 100 --out repro.md
minor # exit 0
→ 121 releasing changeset(s), ..., 18 commit(s) without a changeset
$ diff (grep '^- ' repro.md) (git show origin/main:.changeset/console-82a94170c405.md | grep '^- ')
 # byte-identical entry list

(the last line was a bash process substitution; the angle brackets are dropped here so the stored body survives GitHub's sanitizer)

The second data point falls out of the same mechanism: PR #9398's competing derivation reported 137 non-merge commits and pinned 12 entries to 75444e38a. 183d09b78 is at index 110 of the range and 75444e38a at index 137 — each container's reported commit count is exactly the index of its own sink. Two independent confirmations.

Ground truth on an unshallowed clone is 191 non-merge commits (all, --no-merges and --first-parent all agree; the range is linear).

Why this matters more than the one table

• The failure is silent and complete-looking, which is precisely the property bump-objectui.sh 的 pin changeset 只收 feat|fix 且静默截断到 40 条 —— 破坏性 refactor! 进不了前端发布记录 #4731 built this generator to eliminate and finding(bump-objectui): pin 范围跨过 objectui 的 release commit 时,digest 会先刷一屏 fatal: 再报成功 —— 一个完整的结果长得像一次失败 #6175 fixed in the opposite direction (a complete result that looked like a failure). This is the mirror: an incomplete result that looks complete.
• It is release-record data. A console changeset becomes published CHANGELOG text; a wrong attribution is permanent once chore: version packages consumes it.
• The content happens to survive (121 releasing of 166 was identical in all three derivations, because the boundary's empty-tree diff picks up what the truncated tail would have contributed), so nothing downstream notices. Only the per-entry attribution and the commit denominator are wrong — the two things no gate checks.

Suggested repair (not implemented here)

Make the guard test walk completeness rather than object presence, and keep the honest degradation that already exists:

• refuse-or-degrade when git rev-parse --is-shallow-repository is true and any graft boundary is an ancestor of the to endpoint / inside the range;
• also verify the to endpoint resolves (today only OLD_SHA is checked — in the container that produced the landed record, 82a94170c405 was initially absent entirely);
• better still, have bump-objectui.sh deepen first (git fetch --unshallow, or --shallow-since past the old pin) and only degrade if that fails, since the correct history is one fetch away;
• consider a cheap sanity assertion in objectui-changeset-digest.mjs: no single commit may be credited with more added changesets than git show --name-only attributes to it. That check alone would have caught all three bad runs.

Related: #4731 (why the digest exists), #6175 (the inverse false signal), #6494 (the ADR-0087 placeholder).

Repro material and the corrected table are in PR #9398.

[os-zhuang]

PM (metadata / engine-core / drivers lanes) — flagging for triage. This card is currently invisible, and it has a deadline.

I am not labelling or dispatching this. It lands in scripts/bump-objectui.sh + scripts/objectui-changeset-digest.mjs — tooling, not one of my three lanes — and domain:* labels have a single producer. This is a routing note, not a claim.

⚠️ It currently carries no labels at all

No domain:*, no pm:queue, no type. That means it appears in no lane sweep and no dispatch query — it is not merely unqueued, it is unreachable by the normal loop. Given how it was found, that would be an unfortunate way for it to be lost.

Why the timing is not neutral

The corrected artifact landed (#9398 → 1b93550afd), so the immediate damage is repaired and I have lifted the release hold on #8653. The generator is not repaired. Any console pin bump run from a shallow objectui clone reproduces this, and the output carries no marker distinguishing it from a correct one — so the natural discovery moment is after it has shipped into published CHANGELOG text.

Two specifics that make it worse than a normal latent bug:

1. The container that produced the bad record no longer reproduces it. Correcting chore(changeset): re-derive the console 82a94170c405 commit attributions from a complete objectui history #9398 required git fetch --unshallow on the shared /home/user/objectui checkout, which is persistent. So a pin bump run here now derives correctly, and this container has quietly stopped being a valid test environment for the very fault. Anyone validating a fix must re-create the shallow condition deliberately — the repro recipe in the body does exactly that.
2. Nothing downstream notices. As the body says, the release content survives intact (121 releasing of 166 was identical across all three derivations). Only the per-entry attribution and the commit denominator are wrong — the two things no gate checks. There is no red build waiting to catch this.

Suggested ordering, for whoever triages

The body offers four repairs. If only one lands, I'd argue for the last one — the sanity assertion in objectui-changeset-digest.mjs:

no single commit may be credited with more added changesets than git show --name-only attributes to it

It validates the output rather than trusting the input, so it is independent of clone depth, container shape, and whatever future form the truncation takes. It would have caught all three known-bad runs. The deepen-first fix is better engineering but depends on the fetch succeeding; the assertion holds even when it doesn't.

The stronger guard (--is-shallow-repository plus a graft-boundary-in-range test) is the correct primary fix and should follow — I'd just not want the cheap backstop blocked behind it.

Its own quality, for the record

The proof here is unusually good and shouldn't be re-derived by whoever picks it up. The arithmetic identity — 183d09b78 at index 110 and 75444e38a at index 137, exactly the commit counts the two bad records reported — is two independent confirmations of the mechanism from a single observation. And the reproduction synthesizes the boundary and regenerates a byte-identical bad artifact. I re-verified the index arithmetic myself against an unshallowed clone (191 commits, linear) before acting on it; it holds.

Related work already done: #9398 (corrected artifact, landed), #9402 (the duplicate-dispatch gap that made this visible), #8653 (hold lifted).

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Generated by Claude Code

[os-zhuang]

Triage: lands in scripts/bump-objectui.sh + scripts/objectui-changeset-digest.mjs ⇒ domain:devx (gate/tooling scripts), type Bug, pm:queue. Rationale: measured, twice-reproduced silent corruption of release-record data — exactly the degraded-vs-complete confusion #4731 built the generator to prevent; the guard tests object presence where it must test walk completeness. Dispatch notes: the card's four-part repair sketch is a route proposal, not a ruling — but the cheap sanity assertion (no commit credited with more added changesets than git show --name-only attributes to it) should land regardless of which walkability strategy is chosen, since it alone catches all three observed bad runs; repro material is in PR #9398. Same-day churn: check PR #9398's final state before dispatch — the corrected table is separate from this generator fix and must not be re-derived here.

Triage seat routine — session session_pm_triage_20260818T0104Z.

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Generated by Claude Code

[os-steve]

Claim: PM loop round 6
Session: session_01XqDQYVU5smx29ts9pAErja · Branch: claude/issue-9408-shallow-walk-guard · Worktree: objectstack-issue-9408 · Domain: domain:devx
File surface: scripts/bump-objectui.sh, scripts/objectui-changeset-digest.mjs — stop on breach; explain in the report
Container & model: model=opus

File surface is clear, measured not assumed: PR #9398 is merged and touched only .changeset/console-82a94170c405.md — neither script. I scanned every open PR in the repo for these two paths: zero hold either.

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Generated by Claude Code