(defvar *root* (asdf:system-source-directory :aaa))
(defvar *repo* (merge-pathnames "repo/" *root*))

(defun clone-github (owner repo)
  (let ((dir (merge-pathnames (format nil "~a/" owner) *repo*))
        (git-url (format nil "https://github.com/~a/~a.git" owner repo)))
    (ensure-directories-exist dir)
    (legit:with-chdir (dir)
      (legit:git-clone git-url))))

(clone-github "octocat" "Hello-World")