Bug#1072187: Just followed what is advised in the apt changelog

[Eric Valette]

Found in apt-listchange message:

    ---------------- changelog extract -----------------
systemd (256~rc3-3) unstable; urgency=medium

   - /tmp/ is now by default a tmpfs, via the tmp.mount unit provided 
upstream.
     The previous setup can be retained simply by masking the unit 
locally with:

     systemctl mask tmp.mount

     or:

     touch /etc/systemd/system/tmp.mount

    --------------------------------------------------------

-- 
Eric Valette