anchor.diff:      (make-pathname :directory (pathname-directory *load-truename*))
       "Directory containing the protobuf source code."))
   
  -(defun resolve-relative-pathname (pathname)
  +(defun resolve-relative-pathname (path)
     "When PATHNAME doesn't have an absolute directory component, treat it as
   relative to the protobuf source directory."
  -  (let ((directory (pathname-directory pathname)))
  +  (let* ((pathname (pathname path))
  +         (directory (pathname-directory pathname)))
       (if (and (list directory) (eq (car directory) :absolute))
           pathname
           (merge-pathnames pathname *protobuf-directory*))))
  
positive.code: ;;; Teach ASDF how to convert protocol buffer definition files into Lisp.
  
  
  (defparameter *protoc* (resolve-relative-pathname #p"google-protobuf/src/protoc")
    "Pathname of the protocol buffer compiler.")
  
  (defclass proto-file (cl-source-file)
  
negative.code:    (:proto-file "unittest"
      :proto-pathname "google-protobuf/src/google/protobuf/unittest"
      :depends-on ("unittest_import")
      :proto-search-path ("google-protobuf/src/"))
     ))
  