anchor.diff:  
   (declaim (ftype (function (&optional (or symbol string pathname))) list-installed))
   (defun list-installed (&optional (profile '%current-profile))
  -  "Return the installed package outputs in PROFILE as a list of (NAME OUTPUT).
  +  "Return the installed package outputs in PROFILE as a list of (NAME (:VERSION :OUTPUT)).
   PROFILE is a full path to a profile."
     (guix-eval
      '(use-modules
        (guix profiles))
   
  -   `(map (lambda (entry)
  -           (list (manifest-entry-name entry)
  -                 (manifest-entry-output entry)))
  +   `(define make-output ,%make-output)
  +
  +   `(map make-output
            (manifest-entries
             (profile-manifest ,(namestring profile))))))
   
  
positive.code:          (+ 1 count))
         1)
        result)))
  
  ;; TODO: Find a fast way to compute the output-paths.
  (defun package-output-paths (name)
  
negative.code:          l
           (list l)))
  
     `(define make-package ,%make-package)
  
     '(fold-packages
       (lambda (package result)
         (cons
          (make-package package)
          result))
       (list))))
  
  (defun package-dependents (name)        ; TODO: Unused?
  