# REVIEW — phase `samever` (Adversary writes here)

**Phase:** samever — step back to older base when canonical == head version (no same-version upgrade)
**SSOT:** `/srv/cc-ci/cc-ci-plan/plan-phase-samever-older-base-fallback.md`
**Adversary loop started:** 2026-06-17T04:09Z
**Adversary clone:** /srv/cc-ci/cc-ci-adv

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## Gate verdicts

(none yet — waiting for Builder M1 claim)

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## Orientation @2026-06-17T04:09Z

Phase `samever` plan created 2026-06-17T03:56Z. Builder has not yet started (no STATUS-samever.md).

**Root cause confirmed (cold-read of resolver, lines 133–148 of run_recipe_ci.py):**
```python
rec = canonical.read_registry(recipe)
if rec and rec.get("version"):
    return BasePlan(
        "version",
        rec["version"],
        None,
        f"last-green (warm canonical, status={rec.get('status')})",
    )
```
The warm-canonical path returns `canonical["version"]` WITHOUT checking if it equals the head version.
The resolver is not passed the head's semantic version (only `head_ref`, a commit sha), so it cannot compare.

**Current unit tests (8 tests in tests/unit/test_upgrade_base.py) — none cover canonical==head:**
- test_upgrade_not_in_stages_skip
- test_expected_na_upgrade_skip_even_with_canonical_and_override
- test_explicit_override_wins_over_canonical
- test_last_green_warm_canonical_is_primary  ← uses canonical["version"]="0.6.0+3.1.1", HEAD="aaaa1111head" (different version — correct but doesn't test the same-version edge)
- test_main_tip_fallback_when_no_last_green
- test_head_equals_main_tip_skip
- test_no_canonical_no_main_skip
- test_expected_na_other_rung_does_not_suppress_upgrade

**Key utilities available for the fix:**
- `warm_reconcile.recipe_tags(recipe)` — returns all git tags from recipe clone
- `warm_reconcile.sort_versions(tags)` — ascending sort of version tags (coop-cloud semver)
- `warm_reconcile.latest_version(tags)` — the newest tag
- Head version read from compose.yml: `coop-cloud.${STACK_NAME}.version` label at `abra.recipe_dir(recipe)/compose.yml` (head checkout already at that path when resolver runs)

**M1 verification plan (what I'll cold-verify when claimed):**
1. Resolver reads head version from compose.yml (inspect the parsing — look for compose YAML read + `coop-cloud.*version` label extraction)
2. New chain: override → (canonical if canonical≠head_version) → (newest older published if canonical==head_version) → main-tip → skip
3. Unit tests added: at minimum canonical==head→step_back, canonical≠head→unchanged, no_older_published→skip, version ordering correct
4. Run `python -m pytest tests/unit/test_upgrade_base.py -v` cold from own clone
5. Confirm OVERRIDE, EXPECTED_NA, main-tip, skip paths are untouched (regression: existing 8 tests still pass)
6. Teeth check: a "broken base" scenario should still fail (unit test or from plan F1d-2 evidence)

**M2 verification plan:**
1. Cold-on-latest run on an enrolled recipe whose canonical == latest (seed the canonical to latest, then trigger cold run)
2. Evidence in logs: `base_version < head_version` (not a no-op, not a skip)
3. Re-run discourse #4 or equivalent version-bump PR → UNAFFECTED (canonical→head path still uses canonical)
4. Spot-check ≥1 other recipe

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## Adversary findings

(empty — phase not yet started)

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## Break-it probes log

(none yet)