anchor.diff:  (defun exec (args)
     #+(and unix sbcl)
     (execvp (first args) args)
  +  #+(and unix ccl)
  +  (ignore-errors
  +    (ccl:with-string-vector (argv args) (ccl::%execvp argv)))
     (run-program args)
     (quit -1))
   
  
positive.code: (defun getenv (x)
    #+sbcl(sb-posix:getenv x)
    #+clisp(ext:getenv x)
    #-(or sbcl clisp) (funcall (read-from-string "asdf::getenv") x))
  
  (defun ros-opts ()
    (or *ros-opts*
  
negative.code:     (ignore-errors(funcall (read-from-string "asdf::quit") ret))
      #+sbcl(ignore-errors(funcall (read-from-string "cl-user::exit") :code ret))
      #+sbcl(ignore-errors(funcall (read-from-string "cl-user::quit") :unix-status ret))
      #+clisp(ext:exit ret)
      #+ccl(ccl:quit ret)))
  
  (defun run-program (args &key output)
    (if (ignore-errors #1=(read-from-string "uiop/run-program:run-program"))
  