import type { Readable } from 'node:stream';
export declare function formatError(error: unknown): string;
export declare function isPlainObject(value: unknown): value is Record<string, unknown>;
export declare function cloneValue<T>(value: T): T;
export declare function destroyQuietly(stream: Readable): void;
export declare function mergeDeep<T extends Record<string, unknown>>(base: T, patch: Record<string, unknown>): T;