Faultline

Identify groups that began firing after a deploy or release.

1. Resolve $ARGUMENTS to an ISO 8601 timestamp.
   • If the user gave an ISO timestamp, use it directly.
   • If they gave a relative phrase (30m ago, 2h ago, yesterday at 3pm), convert it.
   • If they gave nothing, ask: what's the deploy timestamp or commit time?
2. Call list_error_groups with since: <timestamp> and the default limit.
3. Filter the response to groups where first_seen_at >= <timestamp> — these are new groups, not just groups that were also hit before the deploy. This is the regression signal.
4. Render: id | exception_class | message | first_seen_at | occurrences_count. Sort by first_seen_at ascending so the earliest regression is first.
5. If any candidates are found, suggest investigating the earliest one with /debug <id> — its backtrace will point at the code introduced by the deploy.

If the result is empty, the deploy looks clean from Faultline's perspective. Mention that errors filtered by ignored_exceptions won't show up here either.

Source: dlt/faultline — distributed by TomeVault.