What causes "get next child ID: iterate children: %w" in gastownhall/beads?

Retry the create; iteration-level connection errors are typically transient.

get next child ID: iterate children: %w

Error message

get next child ID: iterate children: %w

What it means

After the child-ID loop finishes, rows.Err() reports any deferred iteration error (e.g. connection loss during streaming); bd wraps it as "get next child ID: iterate children: %w". This catches failures that only surface after all rows appear consumed, preventing an undercounted child number.

Source

Thrown at internal/storage/issueops/child_id.go:48

		  AND id NOT LIKE CONCAT(?, '.%%.%%')
	`, issueTable), parentID, parentID)
	if err != nil {
		return "", fmt.Errorf("get next child ID: query existing children: %w", err)
	}
	defer rows.Close()

	for rows.Next() {
		var id string
		if err := rows.Scan(&id); err != nil {
			return "", fmt.Errorf("get next child ID: scan child row: %w", err)
		}
		_, childNum, ok := ParseHierarchicalID(id)
		if ok && childNum > lastChild {
			lastChild = childNum
		}
	}
	if err := rows.Err(); err != nil {
		return "", fmt.Errorf("get next child ID: iterate children: %w", err)
	}

	nextChild := lastChild + 1

	//nolint:gosec // G201: counterTable is one of two hardcoded constants.
	if _, err := tx.ExecContext(ctx, fmt.Sprintf(`
		INSERT INTO %s (parent_id, last_child) VALUES (?, ?)
		ON DUPLICATE KEY UPDATE last_child = ?
	`, counterTable), parentID, nextChild, nextChild); err != nil {
		return "", fmt.Errorf("get next child ID: update counter: %w", err)
	}

	return fmt.Sprintf("%s.%d", parentID, nextChild), nil
}

View on GitHub (pinned to 71377f2769)

Solutions

Retry the create; iteration-level connection errors are typically transient.
Increase timeouts / avoid cancelling bd during large child creation batches.
Verify child numbering afterwards (bd show parent) to ensure no duplicate child IDs were produced before the retry.
For remote Dolt servers, check network stability; prefer local embedded mode for very large parents.

Defensive patterns

Strategy: retry

Try / catch

if err := rows.Err(); err != nil { /* inside lib */ }
// caller side:
if err != nil {
    tx.Rollback()
    return retry(fmt.Errorf("iterate children failed: %w", err))
}

Prevention

Avoid cancelling bd commands during large hierarchical creates.
Increase DB timeouts for parents with many children.
Prefer embedded/local Dolt mode when streaming large result sets over unreliable networks.
Always retry the whole transaction after an iteration error; partial state rolls back.

When it happens

Trigger: Completing rows.Next() iteration when the connection broke mid-stream, the context was cancelled during iteration, or the driver hit a protocol error after partial reads.

Common situations: Large parents with thousands of children streamed over a flaky remote Dolt connection; cancelled bd commands mid-create; server timeouts on long result sets.

Related errors

AI-assisted analysis of gastownhall/beads@71377f2769 (2026-08-30). Data as JSON: /api/errors/6324821f7dd37a36. Report an issue: GitHub.