/**
 * The label a source file is reported under: its path relative to the
 * working directory, falling back to the absolute path outside of it.
 *
 * @param filePath - Absolute path of the source file.
 * @returns The display label.
 */
export declare function sourceLabel(filePath: string): string;
/**
 * Formats a thrown value for the error stream.
 *
 * @param error - The thrown value.
 * @returns Its message.
 */
export declare function formatError(error: unknown): string;