(define (read-response-v2 port backend operation)
  (let ((response (read port)))
   (match response
          (("error" err) (protocol-error (sprintf "Error from backend: ~s" err) backend operation))
          ((log value)
           (for-each (lambda (logentry)
                       ((backend-log!) (car logentry) (cdr logentry)))
                     log)
           value)
          ((log)
           (for-each (lambda (logentry)
                       ((backend-log!) (car logentry) (cdr logentry)))
                     log)
           (void))
          (else (error "Malformed response from backend" response)))))