Some changes are needed to build on debian because of the switch of the guest OS to bionic.
lxc that comes with debian is not high enough version to support bionic (the minimum is 2.1.1), so need to build from scratch.
debootstrap that comes with debian will give the following error:
$ bin/make-base-vm --lxc --suite bionic --arch amd64
E: No such script: /usr/share/debootstrap/scripts/bionic