root@raspberrypi:/var/www/wordpress# apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages have been kept back:
  gnome-themes-standard libqt4-dbus libqt4-network libqt4-svg libqt4-xml libqtcore4 libqtgui4
  qdbus
The following packages will be upgraded:
  cups-bsd cups-client cups-common libcups2 libcupsimage2 lsb-base scratch tasksel tasksel-data
9 upgraded, 0 newly installed, 0 to remove and 8 not upgraded.
21 not fully installed or removed.
E: Could not get lock /var/cache/apt/archives/lock - open (11: Resource temporarily unavailable)
E: Unable to lock directory /var/cache/apt/archives/