function done( error, stdout, stderr ) {
		if ( error ) {
			debug( 'Child process error: %s. pid: %d.', error.message, child.pid );
			return clbk( error );
		}
		debug( 'Child process closed. pid: %d.', child.pid );

		proc.stdout.write( stdout );
		proc.stderr.write( stderr );

		clbk( null, child.pid, script );
	}
Callback invoked upon child process termination.

@private
@param {(Error|null)} error - error object
@param {(Buffer|string)} stdout - standard output
@param {(Buffer|string)} stderr - standard error
@returns {void}