The first of these scripts mashes the current branch's code over that of
a pre-existing subiquity snap.
The second uses the first to mash the current branch's code over the
subiquity snap from an ISO and then creates a new ISO with this new
snap.
It's all a bit terrifying but being able to get your changes into a
bootable ISO in about 30s is quite a large improvement on building the
snap from scratch.
Michael Hudson-Doyle