sirupsen/logrus · error

failed to marshal fields to JSON, %w

Error message

failed to marshal fields to JSON, %w

What it means

Error "failed to marshal fields to JSON, %w" thrown in sirupsen/logrus.

Source

Thrown at json_formatter.go:133

			data[f.FieldMap.resolve(FieldKeyFunc)] = funcVal
		}
		if fileVal != "" {
			data[f.FieldMap.resolve(FieldKeyFile)] = fileVal
		}
	}

	b := entry.Buffer
	if b == nil {
		b = new(bytes.Buffer)
	}

	encoder := json.NewEncoder(b)
	encoder.SetEscapeHTML(!f.DisableHTMLEscape)
	if f.PrettyPrint {
		encoder.SetIndent("", "  ")
	}
	if err := encoder.Encode(data); err != nil {
		return nil, fmt.Errorf("failed to marshal fields to JSON, %w", err)
	}

	return b.Bytes(), nil
}

View on GitHub (pinned to 457e372460)

When it happens

Trigger: Thrown at json_formatter.go:133 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of sirupsen/logrus@457e372460 (2026-08-16). Data as JSON: /api/errors/e809020a6c827671. Report an issue: GitHub.