ship-drift reports '0 agents merged-but-unshipped' while all 7 dev-lead stubs are 29-181 commits behind — it compares the 'next' channel, which no stub pins (the #1592 detector is blind to #1592) #1049

canary-rollout drift's ship-drift report is meant to be the detector for petry-projects/.github-private#1592 ("merged ≠ shipped"). It currently reports the fleet as fully shipped while every dev-lead caller stub is 29–181 commits behind, because it measures the wrong tag.

Observed

Run 33454620632 (canary-rollout drift), 2026-09-01:

== agent_ref ship-drift: next channel vs host main (agent_ref-consumed paths) ==
  ci-failure-analyst: shipped — next (33451103a2cf) == petry-projects/.github-private main HEAD
  dev-lead: shipped — next (33451103a2cf) == petry-projects/.github-private main HEAD
ship-drift summary: 0 agent(s) with merged-but-unshipped agent_ref changes

0 agent(s). Meanwhile, what the stubs actually pin:

Seven repos, none current, report clean.

Cause

scripts/canary-rollout.sh ~2578:

a_next="$(channel_commit "$a" next)"
a_main="$(_gh_head_sha "$a_host" "$a_defbranch")"
...
if [ "$a_next" = "$a_main" ]; then
  echo "  $a: shipped — next (${a_next:0:12}) == $a_host main HEAD"
  continue
fi

It compares the next channel to host main. No caller stub pins next — every stub pins a ring/stable tier. So the check answers "has autocut cut a candidate?" and then labels the answer shipped.

The block's own header comment states the intended semantics, and the implementation does not match it:

# pinned channel has NOT yet shipped — the exact failure mode where a PR merges, CI stays
# green, the issue closes, and the change reaches nobody.

That is exactly #1592. The detector for it is measuring next.

Why this is worth fixing rather than tolerating

next being current is the weakest possible signal — it only proves autocut ran. The whole point of #1592 is that autocut working and the fleet being current are independent: autocut has been cutting dev-lead releases normally (up to v139.4.0) the entire time the fleet sat on July code. So this report is not merely incomplete — it is reliably green precisely in the failure mode it exists to catch, and it has been green throughout the ~3 weeks the fleet has been stale.

It also actively misleads recovery work: the natural read of 0 agent(s) with merged-but-unshipped agent_ref changes is "nothing to do here."

Acceptance criteria

• Ship-drift resolves, per agent, the tag each caller stub actually pins — read the uses: ref (and agent_ref:) from each ring member's stub — and compares that commit against host main over the agent_ref-consumed paths.
• Report per repo, not just per agent: different members legitimately sit on different tiers (.github on ring0, TalkTerm/bmad on ring1, the rest on stable), so one row per agent cannot express the state.
• Distinguish expected ring lag from stuck. A stable-tier repo trailing next is normal canary behaviour; the same repo trailing by 181 commits since 2026-07-10 is not. Age or ring-distance thresholds, not raw inequality — otherwise the report is green-when-broken (today) or noisy-always (naive fix), and both get ignored.
• Flag a pin that no promotion can advance — a stub pinned to a tag outside the agent's current major line (v1-* while the agent is on major 139) is unreachable by promotion and should be loud. That single check would have caught #1592 on day one.
• Keep the existing next vs main check as a separate, differently-named line (it is a genuine autocut-health signal), so the two are not conflated.
• Regression test on the current real shape: 7 stubs on v1-*, agent on major 139, next == main → must not report 0 agent(s).

Related

• petry-projects/.github-private#1592 — the condition this should detect
• canary gate: a v-scoped channel tag shadows the release tag in _gh_candidate_cut_date, so any cross-repo agent adopting v<M>-<tier> channels is permanently BLOCKED (indeterminate) — blocks #1592 #1046, canary gate counts a concurrency-EVICTED run (cancelled, 0 steps executed) as cum_fail — dev-lead next->ring0 is sitting on a false REGRESSION recommending rollback; blocks #1592 #1047 — the two gate bugs blocking #1592's fix
• Story (F): major-version boundary in the channel/ring model [#604] #657 (major-scoped channels, F4) — where the v<M>-<tier> vs bare-tier split originates