Calamares is a generic Linux installer.
It is used by Lubuntu and StudioLinux
within the Ubuntu family.
(Also Manjaro, KDE neon, OpenMandriva...)
With Ubuntu potentially dropping support for ubiquity,
(since it is developing an alternative in flutter),
it would be nice to support Calamares well.
One nice thing - it even works (as a live CD)
when you pick "just install" from the initial boot menu.
It fails to find the ubiquity installer,
and just boots up into live mode anyway.
warn if genisoimage and snaps have not been removed.
The normal "mkisofs" provided on Ubuntu is genisoimage,
which has a limit of a 4GB file able to be added to an ISO.
Since the file system is squashed into one big file,
this limit is easily reached if snaps are included.
Unfortunately the alternative mkisofs is not easy to find,
so it is hard to recommend something to the user
at this point, other than to remove snaps.
wasta-core provides wasta-remove-snaps, which keeps
apt snapd installed, but which removes all of the snaps
(which would be updated immediately after OS install anyway).
In my testing, the entire Ubuntu 24.04 (without snaps)
took 2GB, but with snaps it exceeded the limit
(with basically only firefox as a functional snap).
Without the warning, the user would go through
the entire ISO build process, only to fail at the last step.
limit the version comparison to major and minor version numbers
Ubuntu 24.04 exposed the weakness in taking the version at face value.
4.6.1 >= 4.4 gave an input error, because a number cannot have
two decimal places. So limit it to 4.6. Zero-pad the minor version
since it isn't that hard to get to version to .10 or higher.
