Two schema changes the fixes in the following commits build on (BUGS.md B-09,
B-04):
ix_rounds_single_active is a unique index over the constant expression (1),
restricted to the active statuses, so the table holds any number of closed
rounds and only ever one live one. Rounds never overlapping was previously
enforced only by a read-then-insert in open_new_round_if_needed, which two
concurrent callers can both pass — and a second stuck "open" row blocks every
future round forever, since get_active_round matches on status.
The migration doesn't create that index blind: an instance that already has two
active rounds (the very bug) would fail mid-migration with an opaque
IntegrityError, so it first closes the stale duplicates and keeps the newest —
which is what get_active_round was already doing silently. Verified against a
DB seeded with an 'open' plus a 'closing' round.
pending_transactions.failure_reason is for the reconciler added next: when it
gives up on a transaction, an operator needs to see whether it was dropped or
rejected. The PendingTransaction docstring now also documents the full status
lifecycle (building -> pending -> confirmed | failed), since "building" is new
and load-bearing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
davideandClaude Opus 5
cc88763a9d