Same hazard as the package build, with the cluster on the receiving end: a
branch behind main builds images missing whatever landed there, and deploy-k8s.sh
pins that sha in Pulumi — making the stale build the cluster's source of truth.
build-mcpd.sh gets its own call because it is run standalone as well as from
deploy-k8s.sh, so neither can rely on the other having checked.
`--dry-run` is exempt. It builds and cuts over nothing, and blocking a read-only
inspection is exactly what teaches people to export MCPCTL_ALLOW_BEHIND_MAIN=1
permanently — which would disable the gate for the real deploys too.
The failure text is now artifact-agnostic ("produce an artifact" / "shipping
it"), since one helper now speaks for packages, images and deploys.
Verified against a synthetic ref one commit ahead: build-mcpd.sh exits 1 before
any docker work, and deploy-k8s.sh exits 1 before the test gate, the pg_dump,
the image build and pulumi. Neither the working tree nor HEAD was moved to test
this — the ref was built with git commit-tree and deleted afterwards.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019wUmrfkVQR6CKcYKxENq7k
Everyone branches off main and builds from their own branch. A branch that is
behind main still builds and installs perfectly — it just packages a binary
missing whatever landed on main meanwhile, and `rpm -U --force` overwrites the
good one with it. Nothing reports an error; the release succeeds and the feature
simply vanishes from the installed CLI.
That is what happened today: a build from a stale checkout replaced
/usr/bin/mcpctl with one that has no `statusline` command at all, months after
the status line landed on main (`mcpctl statusline` -> "unknown command").
`check-main-sync.sh` fetches main, compares, and fails before any work happens,
listing the commits the branch is missing and the merge that fixes it. Sourced
by build-rpm.sh and build-deb.sh — both are run standalone, so neither can rely
on the other having checked.
A hard failure rather than a warning: a warning scrolls past in a build log, and
the whole point is to stop before the artifact exists.
MCPCTL_ALLOW_BEHIND_MAIN=1 is the escape hatch for a deliberate old-tree build;
MCPCTL_BASE_BRANCH retargets the comparison. Offline it degrades to the last
fetched origin/main, then a local main, saying which it used; outside a git
checkout it skips.
Verified: passes on this branch (up to date with main); against a synthetic ref
one commit ahead, build-rpm.sh aborts with exit 1 before ensure_build_deps and
before any compilation; the escape hatch bypasses it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019wUmrfkVQR6CKcYKxENq7k
