mk-sbuild --target armhf --name "vivid-overlay" vivid

log in to newly created chroot:
  sudo schroot -c source:vivid-overlay-armhf -u root
and run

echo "deb http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu vivid main " > /etc/apt/sources.list.d/vivid-overlay.list
echo "deb-src http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu vivid main" >> /etc/apt/sources.list.d/vivid-overlay.list
apt-key adv --keyserver keyserver.ubuntu.com --recv-keys ECF1204C

apt update