The socket library failpoint for 'recv' does not share a conditional expression with the evaluation of the return value of 'recv': instead, it is currently placed in the error handling function _handleRecvError. This is too late: if the failpoint is enabled, it will only be triggered if 'recv' actually fails, rather than making it appear as if 'recv' failed. The failpoint must be moved earlier, so that it can influence the apparent success or failure of recv.