Scidb's repository has just reappeared, so checkout of newest version r880 is possible.
Please don't forget that the repository URL has changed some weeks ago, see <http://sourceforge.net/mailarchive/forum.php?thread_name=trinity-6aa7a981-c73c-45b3-af9c-2186f39e975f-1370344708229%403capp-gmx-bs39&forum_name=scidb-users> how to switch the repository URL.