hashicorp/nomad · error

failed to get source last index: %w

Error message

failed to get source last index: %w

What it means

Fires in verifyMigration when querying LastIndex on the source raft log store returns an error; the migration's index-range comparison cannot proceed because the source range is unreadable.

Source

Thrown at helper/raftutil/migrate.go:259

// verifyMigration performs sanity checks on the migrated data.
// src and dst should implement both LogStore and StableStore interfaces.
func verifyMigration(src interface {
	raft.LogStore
	raft.StableStore
}, dst interface {
	raft.LogStore
	raft.StableStore
}) error {
	// Verify log index ranges match.
	srcFirst, err := src.FirstIndex()
	if err != nil {
		return fmt.Errorf("failed to get source first index: %w", err)
	}

	srcLast, err := src.LastIndex()
	if err != nil {
		return fmt.Errorf("failed to get source last index: %w", err)
	}

	dstFirst, err := dst.FirstIndex()
	if err != nil {
		return fmt.Errorf("failed to get destination first index: %w", err)
	}

	dstLast, err := dst.LastIndex()
	if err != nil {
		return fmt.Errorf("failed to get destination last index: %w", err)
	}

	if srcFirst != dstFirst {
		return fmt.Errorf("first index mismatch: source=%d, destination=%d", srcFirst, dstFirst)
	}

	if srcLast != dstLast {
		return fmt.Errorf("last index mismatch: source=%d, destination=%d", srcLast, dstLast)

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Inspect the source BoltDB store for corruption or lock contention
2. Re-run the migration after fixing the underlying storage issue
3. Fall back to the pre-migration BoltDB backup if verification keeps failing

When it happens

Trigger: Thrown at helper/raftutil/migrate.go:259 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/9e6f1d44588a69e9. Report an issue: GitHub.