The shadow (dee93fa, run 4732) answered the gate: `imagetools inspect
--format` reads `.Image.Config.Labels` against this registry on buildx
v0.36.1. So the reuse check now asks the moving channel tag whether the image
it already points at carries this commit's `fc.revision`, and the r-<rev>
identity tags stop being published.
Three things this removes rather than manages:
A name minted per build that one thing read. Rule 145's narrowing is aimed
exactly there — "a third name for the same thing is upkeep for a model we do
not run."
The -main/-dev qualifier, and the CHANNELLED list behind it. Which tag you
inspect IS the channel, so the distinction has nowhere to live. cmd_identity
goes with it.
A silent expiry nobody wrote down. r-<rev> matches no branch of the
registry's keep_pattern (#3157), so identity tags were prunable past the
newest 10 — a pruned one costs a rebuild, in the safe direction and entirely
invisibly. A label rides inside a tag that has to exist anyway.
It also dissolves #3154 instead of deferring it: a scheduled base refresh
rebuilds :latest with the same revision label, the next unrelated push sees a
match and skips, and the refreshed base survives. Under the tag scheme that
push repointed :latest back to the older base.
The measured detail that shapes the code: a missing label returns an EMPTY
STRING and exits 0. Branching on the exit code would read "no label yet" as
success and skip a build that was needed. So it compares values, and every
uncertain case — absent label, unreachable tag, older image — lands as empty,
never equals a 12-char revision, and falls through to a build.
Reading the specific key matters too. The map carries the base image's labels,
and org.opencontainers.image.version sits right beside ours reading 24.04 on
the agent — a plausible-looking wrong answer.
Expect every artifact to rebuild once on this push: nothing carries a label
yet and it cannot be backfilled, since the reuse path copies a manifest and
config labels are not manifest annotations. One rebuild per artifact, ever,
self-healing after.
test_artifact_identity.py is rewritten around what is now load-bearing. The
CHANNELLED drift test had nothing left to guard; in its place the revision is
asked of git directly, so the file fails if the derivation ever stops being
"the commit this artifact's own shipped files last changed in".