Single failure on a printer with require_previous_success queue items
permanently skipped every downstream + every new item — the
_check_previous_success lookback always walked back to the original
failed row (skipped is excluded from the lookback), and no code path
could dismiss that failure.
Three pieces:
1. PrintQueueItem.gate_acknowledged Boolean column (default False).
SQLite/Postgres-safe ALTER, dialect-branched DEFAULT.
2. _check_previous_success skips rows where gate_acknowledged=True so
acknowledged failures walk past the lookback. Fresh post-resume
failures still gate independently.
3. POST /api/v1/queue/printer/{printer_id}/resume — gated on
QUEUE_UPDATE_ALL — acknowledges failed/aborted items for that
printer AND restores items where
status='skipped' AND error_message='Previous print failed or was
aborted' back to pending in one transaction. Returns
{acknowledged, restored}.
Frontend banner above the active Queue tab surfaces blocked printers,
fires a warning-variant ConfirmModal, and shows a precise toast on
success.
Two bugs in PrintScheduler._check_previous_success:
- Lookback excluded 'cancelled' so user cancellations were walked past
- Lookback included 'skipped', so one skip cascaded indefinitely
Swap to ['completed', 'failed', 'cancelled', 'aborted'] and accept
both 'completed' and 'cancelled' as predecessor success. Real
'failed' / 'aborted' still gate.
One-shot migration in run_migrations resets only the skipped items
whose true predecessor was cancelled — surgical reversal of the exact
bug fingerprint, leaves genuine failure-gated skips alone. Portable
across SQLite and Postgres, idempotent on re-run.
maziggy