multica-ai/multica · error · ErrDuplicatePendingTask

a pending task for this issue and agent already exists

Error message

a pending task for this issue and agent already exists

What it means

Error "a pending task for this issue and agent already exists" thrown in multica-ai/multica.

Source

Thrown at server/internal/service/task.go:583

// ErrAttributionFailClosed signals that a run resolved to no precise accountable
// human and the enqueue is REFUSED rather than started. It covers three cases, all
// of which mean "we cannot guarantee an accountable human for this run" (MUL-4302
// §1/§3.5): the workspace opted into fail-closed; the workspace policy could not be
// read (so we cannot confirm fallback is allowed — fail closed, don't run); or
// owner_fallback has no agent owner to fall back to. Enqueue paths surface it so the
// run never starts.
var ErrAttributionFailClosed = errors.New("attribution: no precise accountable human and enqueue refused (fail-closed policy, policy read failed, or no agent owner)")

// ErrDuplicatePendingTask means a fresh enqueue lost the race to a concurrent
// one: a queued/dispatched task for the same (issue, agent) already exists, so
// the pending-task unique index rejected the insert (#5914). This is a benign
// outcome — a sibling run already covers this target
// — not a server fault. Enqueue paths return it so callers can report a
// success-shaped coalesced outcome / structured 409 instead of surfacing the
// raw Postgres constraint as a 500. It is returned BARE (the raw driver text,
// including the index name, is logged once at debug and never wrapped in) so no
// upper-layer log or response can leak the constraint name (#5914, Elon review).
var ErrDuplicatePendingTask = errors.New("a pending task for this issue and agent already exists")

// isDuplicatePendingTaskErr reports whether err is the pending-task unique-index
// violation (a concurrent enqueue won the race). Accept both names while v1 and
// v2 can coexist during a rolling deploy.
func isDuplicatePendingTaskErr(err error) bool {
	var pgErr *pgconn.PgError
	if !errors.As(err, &pgErr) || pgErr.Code != "23505" {
		return false
	}
	switch pgErr.ConstraintName {
	case "idx_one_pending_task_per_issue_agent", "idx_one_pending_task_per_issue_agent_v2":
		return true
	default:
		return false
	}
}

// applyAttributionFallback applies the workspace's degraded-attribution policy to a

View on GitHub (pinned to 2c0912b6ec)

Solutions

1. Wait for the pending task to finish or cancel it before enqueueing another.

When it happens

Trigger: Thrown at server/internal/service/task.go:583 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of multica-ai/multica@2c0912b6ec (2026-08-15). Data as JSON: /api/errors/882212eed6dcd0bd. Report an issue: GitHub.