PC 2, 7 October 2026 18:34 BST: two rows sat on "exporting this hour's program" for 18 minutes while a third card
mined. The export ran on a thread per card under one lock with no bound on the wait, and a result that never came
left the slot in the building state for ever.
- watchdog::export_wait: inside one interval (the ladder rung, at least 30 s) the row keeps its word; past it the row
names what blocks the export; past two intervals the wait ends and the worker retries on its own interval.
- engine: EXPORT_HOLDER names the card whose export holds the pack lock and for how long, EXPORT_LAST_ERROR the last
failure (the node not at the epoch, no seeds.txt); export_blocker() reads them for the row; build_seq ignores a
late result after the wait ended; a failed export retries on the ladder, never a flat five minutes.
- docs/plans/miner-faults.md: MF-14 with rule, test and gate line.
Test known-failed first: an export that never returns is named at one interval and given up at two.
Gates: app tests 260 + 33 + 8 green on igneum-build-2; the tree gate GREEN, 56 checks.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>