grafana/k6 · error

record length (%d) doesn't match header length (%d)

Error message

record length (%d) doesn't match header length (%d)

What it means

Error "record length (%d) doesn't match header length (%d)" thrown in grafana/k6.

Source

Thrown at internal/js/modules/k6/experimental/csv/reader.go:117

	if toLineSet && r.options.ToLine.Int64 > 0 && r.currentLine.Load() > r.options.ToLine.Int64 {
		return nil, io.EOF
	}

	record, err := r.csv.Read()
	if err != nil {
		return nil, err
	}

	r.currentLine.Add(1)

	// If header option is enabled, return a map of the record.
	if r.options.AsObjects.Valid && r.options.AsObjects.Bool {
		if r.columnNames == nil {
			return nil, fmt.Errorf("the 'asObjects' option is enabled, but no header was found")
		}

		if len(record) != len(r.columnNames) {
			return nil, fmt.Errorf("record length (%d) doesn't match header length (%d)", len(record), len(r.columnNames))
		}

		recordMap := make(map[string]string)
		for i, value := range record {
			recordMap[r.columnNames[i]] = value
		}

		return recordMap, nil
	}

	return record, nil
}

// validateOptions validates the reader options and returns an error if any validation fails.
func validateOptions(options options) error {
	var (
		fromLineSet      = options.FromLine.Valid
		toLineSet        = options.ToLine.Valid

View on GitHub (pinned to 93accf6570)

When it happens

Trigger: Thrown at internal/js/modules/k6/experimental/csv/reader.go:117 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/f696db860a6cc3ad. Report an issue: GitHub.