Fix.

[config] / all_new_2018 / apt-mark / server

# needed to log in to server via ssh
openssh-server
# provides /etc/inputrc and understanding of ctrl+arrow key combos
readline-common
# provides systemd scripts that configure iptables via /etc/iptables/*
iptables-persistent
# this line is here because the shell "read" in install_for_target.sh ignores lines without final newline