## The defect
`clearStaleBlockedBy` keeps a per-task memo of which overlap blocker it
already logged, so a sweep running every few seconds doesn't repeat the
same line forever. The memo was retained only while the card sat in a
column matching the literal `todo` — so on a renamed board it was
dropped on **every** sweep and `still blocked by file scope overlap with
<id>` was re-logged each time.
## Census before / after
| | before | after |
|---|---|---|
| COLUMN guards (backlog) | 9 | **8** |
| `packages/engine/src/self-healing.ts` | 1 | **0 — converted** |
Baseline re-recorded in the same commit; `--strict` green. (Counts
follow #3215, which took 10 → 9.)
## The stated blocker was not real
The note here declined the conversion because the lane prefetch is keyed
on `candidates`, *"which this closure helps build"*. Measured — it does
not:
```
6033| for (const task of blockedTasks) candidates.set(task.id, task);
6034| for (const task of queuedDependencyTasks) candidates.set(task.id, task);
6036| for (const [taskId, lastLoggedBlockerId] of this.preservedQueuedOverlapLogged) { <- only CLEARS memos
```
`candidates` is fully populated two statements earlier, and this loop
only clears memo entries. So the prefetch was hoistable; it now sits
above the loop. That is a pure move of a read-only computation with no
conditional between the two positions.
Reaching the lane clause already proves the id is a candidate —
`!candidates.has(taskId)` is the first arm of the same `||` chain, so
short-circuit means the lane question is only asked for ids the prefetch
covered (`referencedIds.add(task.id)` runs for every candidate).
`lanesOf` still falls back to the legacy set, so an unresolvable
workflow answers exactly as the literal did.
This is the second inherited "too expensive" estimate to fail on
inspection this session (see #3215). Both were written in good faith and
both were checkable in a few minutes.
## One thing typecheck caught that review would not have
`memoTask?.column !== "todo"` was **also** the undefined check, and tsc
narrowed the later clauses on it. Replacing it without that arm compiled
clean to the eye but broke narrowing — `TS18048: 'memoTask' is possibly
'undefined'` on the next line. `|| !memoTask` is now explicit rather
than implied.
## Evidence
The test drives the sweep **twice**, because a single pass cannot
observe a dedup memo at all.
| | pre-fix literal | converted |
|---|---|---|
| `still blocked by file scope overlap` log lines | **2 — FAILS** | **1
— passes** |
Failure message against the pre-fix code: `expected [ [ 'FN-DEPENDENT',
…(1) ], …(1) ] to have a length of 1 but got 2`.
Worth correcting the record: the note called the cost *"a duplicate log
line, not a wrong lifecycle decision"*. The lifecycle half is right —
but it is a duplicate on **every sweep**, so it is recurring log spam,
not a one-off. That is a bigger cost than the note implies, though still
not a correctness bug.
| check | result |
|---|---|
| `census --strict` / `check-fnxc-future-dates` | exit 0 / exit 0 |
| `eslint` / engine `tsc --noEmit` | clean / exit 0 |
| self-healing + overlap suites | 15 / 21 / 6 passed |
| `pnpm test:gate` | exit 0 (744 tests) |
Reused the existing `RENAMED_BOARD_IR` harness in that file rather than
building a new one.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **Bug Fixes**
- Improved cleanup of stale workflow blockers, including renamed
workflow lanes.
- Prevented duplicate overlap warnings during repeated cleanup.
- More reliably preserves valid queued overlaps while ignoring missing
or inactive tasks.
- **Tests**
- Added regression coverage for repeated stale-blocker cleanup and
duplicate warning prevention.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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