anchor.diff:  
   (defparameter *guess-website-patterns*
     '(("//github.com/(.*)\\.git" "https://github.com/" 0 "/")
  -    ("(https://gitlab.common-lisp.net/.*)\.git$")
  -    ("(https://gitlab.com/.*)\.git$")
  +    ("(https://gitlab.common-lisp.net/.*)\.git$" 0)
  +    ("(https://gitlab.com/.*)\.git$" 0)
       ("//mr.gy/(.*?)/(.*?)/" "http://mr.gy/" 0 "/" 1 "/")
       ("(http://(.*?).googlecode.com/)" 0)
       ("//common-lisp.net/projects/(.*?)/" "http://common-lisp.net/projects/" 0)
  
positive.code:       (let ((substitution (substitute-if-matches regex
                                                   location
                                                   substitution)))
          (when substitution
            (return substitution))))))
  
  (defun guess-website (project)
  
negative.code: (defun project-website (project)
    (or (primary-system-website project)
        (guess-website project)
        (cliki-link project)
        (error "Can't determine project website for ~S" project)))
  
  (defun github-properties (url)
    (ppcre:register-groups-bind (user repo)
  