anchor.diff:  (defmethod list-packages ((manager (eql :guix)))
     (mapcar #'database-entry->guix-package (guix-database)))
   
  -(defmethod refresh ((manager (eql :guix)))
  +(defmethod refresh ((manager (eql :guix))) ; TODO: Unused?
     (declare (ignore manager))
     (setf *guix-database* nil))
   
  
positive.code:                         :output '(:string :stripped t)
                          :error-output :output))))
  
  (defun package-output-paths (name)
    "Computing the output-paths in `generate-database' is too slow, so we do it just-in-time instead."
    (guix-eval
  
negative.code:      (guix utils)
       (gnu packages))
  
     `(define find-package ,%find-package)
  
     '(define* (package-output-paths package)
       "Return store items, even if not present locally."
  