fix(ci): ask cut-rc whether the objectui pin is ON main, not whether the object exists

.github/workflows/cut-rc.yml

@@ -272,9 +272,11 @@ jobs:
  OBJECTUI_ROOT="${RUNNER_TEMP}/objectui"
  # FULL clone, not shallow, and still a measured requirement rather than
  # caution. Two reasons, both surviving #10134:
- # - the check below asks whether the PIN is a real, reachable commit
- # of objectui main; a tip-only shallow clone cannot answer that and
- # would answer "no" for every pin older than the tip;
+ # - the check below asks whether the PIN is reachable from objectui
+ # main; a tip-only shallow clone cannot answer that and would answer
+ # "no" for every pin older than the tip. Necessary, not sufficient:
+ # a full clone carries every branch, main's and otherwise, so it
+ # makes the question answerable without answering it;
  # - build-console.sh builds from THIS clone (it honours
  # $OBJECTUI_ROOT) by adding a worktree at the pin, which needs the
  # pin's tree present.
@@ -284,14 +286,41 @@ jobs:
  git clone --no-tags https://github.com/objectstack-ai/objectui.git "$OBJECTUI_ROOT"
  echo "OBJECTUI_ROOT=${OBJECTUI_ROOT}" >> "$GITHUB_ENV"
 
- # The pin must be IN the clone. Still a real failure mode, and the only
- # objectui-side one left: a pin taken from a branch that never merged,
- # or a main that was rewritten, names a revision nobody can resolve
- # later — and the cut would publish a console built from it.
+ # THE PIN MUST BE ON objectui MAIN — WHICH IS NOT WHAT OBJECT PRESENCE
+ # ANSWERS (#9450). This was one `cat-file -e`, and the sentence it
+ # printed on failure — "not reachable from main (unmerged branch, or
+ # main was rewritten)" — named a case the test cannot see. Measured on
+ # a fresh `--no-tags` clone of objectui, 2026-08-21: 291 commits across
+ # 118 branch tips are present and NOT reachable from main, and
+ # `cat-file -e` says yes to every one of them — including the "branch
+ # that never merged" the message claimed to catch. The clone being FULL
+ # is what OPENS that gap rather than closing it: `git clone` fetches
+ # every branch head, so the more complete the clone, the more non-main
+ # revisions it can vouch for.
+ #
+ # Nothing upstream closes it either — bump-objectui.sh pins
+ # `git rev-parse HEAD` of a local objectui checkout without asking which
+ # branch that is. "The operator happened to be on main" is the whole of
+ # the protection, so ask the question here rather than assume it.
+ #
+ # Three questions, three exits, in this order because the later ones
+ # cannot be asked until the earlier ones hold: `merge-base --is-ancestor`
+ # exits 128 on an absent object — an error, not a verdict — and with no
+ # origin/main it would report "the pin left main", which is this block's
+ # own overclaim wearing a new message.
+ if ! git -C "$OBJECTUI_ROOT" rev-parse --verify --quiet origin/main >/dev/null; then
+ echo "::error::the objectui clone has no origin/main ref, so \"is the pin on main\" cannot be answered in it. Refusing to cut rather than assuming the answer."
+ exit 1
+ fi
  if ! git -C "$OBJECTUI_ROOT" cat-file -e "${OBJECTUI_SHA}^{commit}" 2>/dev/null; then
- echo "::error::the committed pin ${OBJECTUI_SHA} is not present in a fresh full clone of objectui main. It names a revision that is not reachable from main (unmerged branch, or main was rewritten). Fix .objectui-sha in its own PR; do not cut against it."
+ echo "::error::the committed pin ${OBJECTUI_SHA} is not present in a fresh full clone of objectui at all — no branch carries it. It was never pushed, its branch was deleted, or main was rewritten. Fix .objectui-sha in its own PR; do not cut against it."
+ exit 1
+ fi
+ if ! git -C "$OBJECTUI_ROOT" merge-base --is-ancestor "$OBJECTUI_SHA" origin/main; then
+ echo "::error::the committed pin ${OBJECTUI_SHA} exists in objectui but is NOT reachable from objectui main — it names a revision on a branch that never merged. Cutting against it would publish @objectstack/console built from code that is not on main. Fix .objectui-sha in its own PR; do not cut against it."
  exit 1
  fi
+ echo "objectui pin ${OBJECTUI_SHA:0:12}: present in the clone, and reachable from objectui main."
 
  # Detach the clone AT THE PIN so nothing downstream can accidentally
  # read a working tree that is objectui main. build-console.sh builds