(defun from-cache (wdir dir id)
 "Read cache information from *working-directory*/<DIR>/<ID>"
 (let ((cache-path (format nil "~A/~A/~A" wdir dir id)))
  (when (probe-file cache-path)
   (with-open-file (stream cache-path)
    (read stream)))))

(setf *repositories-cache*
 (from-cache "/var/tmp/forgerie/phabricator" "everything" "repositories"))

(forgerie-core:vc-repository-slug (first *repositories-cache*)) ; => "puppet-environment"