anchor.diff:                command :show-cmd nil :prefix "" :output-stream nil)
                #+mcl (ccl::with-cstrs ((%command command)) (_system %command)))
              (call-system (command-string)
  -             (check-result (system command-string)))
  +             (check-result (system command-string) nil))
              (use-system ()
                (if output
                    (with-temporary-file (:pathname tmp :direction :output)
  
positive.code:                      (unwind-protect
                            (slurp-input-stream output stream)
                         (when stream (close stream))
                         (check-result (process-result process)))
                       (unwind-protect
                            (check-result
                             #+(or allegro lispworks) ; when not capturing, returns the exit code!
                             process
                             #-(or allegro lispworks) (process-result process)))))))
             (system-command (command)
               (etypecase command
                 (string (if (os-windows-p) (format nil "cmd /c ~A" command) command))
  
negative.code: (defmethod slurp-input-stream ((x (eql :forms)) stream &key &allow-other-keys)
    (declare (ignorable x))
    (slurp-stream-forms stream))
  
  (define-condition subprocess-error (error)
    ((code :initform nil :initarg :error-code :reader subprocess-error-code)
     (command :initform nil :initarg :command :reader subprocess-error-command)
     (process :initform nil :initarg :process :reader subprocess-error-process))
    (:report (lambda (condition stream)
               (format stream "Subprocess~@[ ~S~]~@[ run with command ~S~] exited with error~@[ code ~D~]"
                       (subprocess-error-process condition)
                       (subprocess-error-command condition)
                       (subprocess-error-code condition)))))
  
  (defun run-program/ (command
                       &rest keys
  