rm -fv etc/apt/sources.list &&
( ! [ -e /etc/apt/sources.list ] || cp /etc/apt/sources.list etc/apt/sources.list)
(cp -v /etc/apt/sources.list.d/* etc/apt/sources.list.d/ || true ) &&
- cp -v /etc/apt/preferences etc/apt/ &&
+ ( ! [ -e /etc/apt/preferences ] || cp -v /etc/apt/preferences etc/apt/ ) &&
apt-key exportall | chroot . apt-key add - &&
chroot . apt-get update &&
echo "Apt::Install-Recommends 0;" > etc/apt/apt.conf.d/local-recommends &&