anchor.diff:          mkdir -p -m 0700 ${cfg.cachedir}
           chown root:root ${cfg.cachedir}
           chmod 0700 ${cfg.cachedir}
  +        mkdir -p -m 0700 ${cfg.cachedir}/$1
           DIRS=`cat /etc/tarsnap/$1.dirs`
           exec tarsnap --configfile /etc/tarsnap/$1.conf -c -f $1-$(date +"%Y%m%d%H%M%S") $DIRS
         '';
  
positive.code: 
      environment.etc =
        (mapAttrs' (name: cfg: nameValuePair "tarsnap/${name}.conf"
          { text = configFile cfg;
          }) cfg.archives) //
        (mapAttrs' (name: cfg: nameValuePair "tarsnap/${name}.dirs"
          { text = concatStringsSep " " cfg.directories;
  
negative.code:           will refuse to run until you manually rebuild the cache with
            <command>tarsnap --fsck</command>.
  
            Note that each individual archive (specified below) has its own cache
            directory specified under <literal>cachedir</literal>; this is because
            tarsnap locks the cache during backups, meaning multiple services
            archives cannot be backed up concurrently or overlap with a shared
            cache.
  
            Set to <literal>null</literal> to disable caching.
          '';
        };
  