declare class MissingEnvVarError extends Error {
}
/**
 * Get an environment variable by name. If a default value is not given, and
 * the variable is empty or missing, throw MissingEnvVarError.
 *
 * If an empty string is acceptable, pass `defaultValue` as "".
 */
declare function getEnv(varName: string, defaultValue?: string | null): string;

export { MissingEnvVarError, getEnv };