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Three instances rolled r1 -> r2 behind a health gate, then a one-way migration. The safe plan fails can-roll-back: the runbook done right, eight steps, ends where r1 is unreachable for good; ct.rules one-way names `migrate` and nothing else. The shortcut drops the health gate and goes dark in four steps. Writing it, writ found a race in the first draft: finish the rollout, decide to roll back, and the migration (guarded on the instances only) runs anyway; the rollback then starts r1 on v2. migrate now also requires target r2. Cross-check 49 -> 52 properties (50 compared); 301 checks. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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Superseded: reached main through #10. |
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Stacked on #6 (base
agent-guardrails).Adds
deployment/: three instances rolled from r1 to r2 behind a health gate, then a migration to v2 that r1 cannot read and that cannot be undone. Faults are one at a time, which the README explains.can-roll-backfails. The witness is the runbook done right in eight steps; it ends at a finished release from which r1 is unreachable for good. The runbook's rollback section stops being true at step 8.one-wayfrom ct.rules, asked with no goal in mind, names exactly one move that cannot be taken back:migrate.target-r2 → replace a → replace b → replace c, and production is dark. It still finishes the release.migratewas guarded on "all instances on r2 and healthy", so finishing the rollout, deciding to roll back, and then migrating anyway left the rollback starting r1 on v2.one-waynamed eleven moves instead of one, and that is how it showed.migratenow also requires target r2. The README tells the story.Cross-check: 49 → 52 properties (50 compared).
./run-tests.sh all: 301 checks, 0 failed.🤖 Generated with Claude Code