(flet
    ((load-subdir (name)
       (make-pathname
        :name nil :type nil :version nil
        :defaults
        (merge-pathnames (concatenate 'string name "/")
                         *load-truename*)))
     (a-i-symbol (name)
       (intern (string name)
               (find-package #.(string '#:asdf-install)))))
  (pushnew (load-subdir "systems") asdf:*central-registry*)
  (asdf:operate 'asdf:load-op :asdf-install)
  (setf (symbol-value (a-i-symbol '#:*locations*))
        `((,(load-subdir "site")
            ,(load-subdir "systems")
            "Semi-local installation")))
  (push '(:absolute "bin")
        (symbol-value (a-i-symbol '#:*shell-search-paths*))))