The ~400-line append this branch made to DECISIONS-LOG.md's tail is what made PR #20
unmergeable: every concurrent branch appends to the same last hunk, and on 2026-09-29
four of the five open PRs conflicted on that one file and nothing else. The prose is
unchanged in substance -- it moves to decisions/2026-09-29-conformance-job-template.md,
the one-file-per-handoff layout PR #24 introduces -- and DECISIONS-LOG.md is no longer
touched by this branch at all.
Carried over in full, including every caveat: the initContainers/ephemeralContainers/env
finding and its measurements, the fixture matrix (65 pass / 13 fail / 0 error / 0 skip),
the hardcoded-clone-URL reasoning, the args shapes that cannot run in-cluster, the
`approval-policy` check that does not exist, and all of the UNVERIFIED items -- nothing
has executed against a cluster, the runner image and Secret do not exist, PR #18 must
merge first, and whether the API server even accepts ephemeralContainers in a Job pod
template is still unestablished.
One claim was WEAKENED rather than restated, per ci/l0.sh's own lesson: `kyverno test`
exits 0 and prints "N tests passed" even when a policy FAILS TO LOAD (every row becomes
Skip / Invalid Policy), which was measured while authoring this very policy. The entry
now says explicitly that the admission proofs rest on `kyverno apply`'s `error: 0,
skip: 0` counts, not on any exit code, and that a green l0 line would not by itself have
established that these rules loaded.
Format is decisions/README.md's: frontmatter (date, branch, title) plus the three
sections ci/decisions-log.sh enforces. The branch is rebased onto main at c59fe9f,
after #24 merged, so that stage is in the base and DID run against this entry.
Gate (toolbox, DEV_KUBECONFIG=/dev/null + ENGINE shim): spec-immutability, decisions-log
(archive frozen, 2 entries well-formed), lint (404 files), l0, render-golden (10),
l1 all green; gitea-settings SKIPPED (no SETTINGS_API_TOKEN) and conformance L2/L3
SKIPPED (CLUSTER_AVAILABLE unset); MERGE GATE UNDETERMINED -- stages that did not run:
gitea-settings -- rc 3. Nothing FAILED, and rc 3 is not green.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
decisions/ — the handoff log, one file per entry
This directory is the decision log. ../DECISIONS-LOG.md is the frozen archive of
everything written before 2026-09-29 and is never edited again (see "The archive is
frozen" below).
Why this exists
DECISIONS-LOG.md was append-only in a single file, and every agent appended to its
tail. Two branches that both append hit the same last hunk, so git cannot
auto-merge them: the second one to be reviewed conflicts, and so does the third, and
the fourth. Measured on 2026-09-29: four of the five open PRs were unmergeable, and
DECISIONS-LOG.md was the only conflicting file in all four:
#22 fix/crafty-oauth2-proxy-signin CONFLICT (content): DECISIONS-LOG.md
#20 feat/conformance-job-template CONFLICT (content): DECISIONS-LOG.md
#19 feat/conformance-trigger-kubeconfig CONFLICT (content): DECISIONS-LOG.md
#18 feat/conformance-runner-image CONFLICT (content): DECISIONS-LOG.md
#17 feat/ci-is-the-approver clean (it touched no log entry)
Nothing was wrong with any of those changes. The log's storage format serialised work that was otherwise parallel, and it got worse with every concurrent branch: N branches produce N-1 rebases, each of which invalidates any gate run that preceded it.
The fix is the obvious one for concurrent appenders: stop sharing a file. Each handoff is its own file. Two agents writing handoffs touch disjoint paths, so there is nothing for git to merge and nothing to conflict. This scales to any number of parallel branches with zero coordination — which is the point, since the agents are deliberately isolated from each other in separate worktrees and cannot coordinate.
There is deliberately no index file and no counter. An index would be a shared
mutable file — exactly the thing that just failed — and a sequence number would have
two agents racing for 0043. The directory listing is the index.
Writing an entry
One file per handoff, named:
decisions/YYYY-MM-DD-<slug>.md
<slug> is lowercase [a-z0-9-]. Use your branch name's last segment — it is
already unique per unit of work, which is precisely the property the filename needs.
A branch fix/crafty-oauth2-proxy-signin handed off on 2026-09-29 writes:
decisions/2026-09-29-crafty-oauth2-proxy-signin.md
The file is YAML frontmatter followed by three required sections:
---
date: 2026-09-29
branch: fix/crafty-oauth2-proxy-signin
title: The Keycloak gate works — Crafty's own login was the wall
---
## What changed
Prose. What you actually did, and why.
## What I verified
The measurements, with their numbers. Quote the field you read, not the prose you
believed. Name the gate result and its exit code.
## What I did NOT verify
Everything else. An honest "UNVERIFIED" is worth more than an optimistic "green" —
this repo has been burned by the difference more than once.
All three headings are required and enforced (ci/decisions-log.sh). They are
CLAUDE.md §7's contract; making them a checked structure is what stops an entry
degrading into "done ✅".
Reading the log
The whole log, oldest first:
ls decisions/[0-9]*.md | sort
The current PM handoff — the newest entry. Ties within a day are broken by what landed
on main last, which is the honest answer, so ask git rather than the filename:
git log --diff-filter=A --format='%H' --name-only -- 'decisions/[0-9]*.md' \
| grep '^decisions/' | head -1
For a quick skim of who said what:
grep -H '^title:' decisions/[0-9]*.md | sort
The archive is frozen
DECISIONS-LOG.md is read-only history. Its SHA-256 is pinned in
decisions/ARCHIVE.sha256 and ci/decisions-log.sh fails the merge gate if the file
changes. That is not ceremony: without it, the next agent to read runbooks/ or an old
CLAUDE.md habit appends to the tail again and re-creates the conflict for everybody
else, silently, one PR at a time.
If the archive genuinely must change (a leaked credential to redact, say), that is a
deliberate, reviewed act: change it, run sha256sum DECISIONS-LOG.md > decisions/ARCHIVE.sha256,
and say in your handoff entry why. Re-pinning is visible in the diff. Appending is not.