“Throw away” linux images in seconds

Generating a new rootfs from scratch in order to test changes to early
parts of the software stack or just to have a pristine environment is
something I needed several times in the past.

Since I use Archlinux in my desktop something that I like is to have a
similar environment in the target test rootfs. I decided to re-use and
improve a script from Kay Sievers to create an installer that can be
booted as a VM, as a container or in bare metal:
arch-installer.sh.
Originally  it was a script to bootstrap a Fedora image and I think …