What's the best way to test mainline Ubuntu without destroying my Kubuntu install?

[Ralf Mardorf]

On Wed, 17 Apr 2019 22:00:45 +0100, Colin Law wrote:
>On Wed, 17 Apr 2019 at 17:30, Christopher Patti <feoh at feoh.org> wrote:
>> Pardon the stupid question but will that overwrite my current GRUB
>> configuration or simply add a new entry to boot Ubuntu/Gnome?  
>
>Not stupid at all.  It will add a new one to the boot list.  The
>default will be the new one and the original will be an option.  To
>put the default back to the original (with the new one an option) boot
>into the original and run
>sudo grub-install /dev/sda   # assuming that sda is the boot drive
>sudo update-grub

AFAIK it will not add anything to the grub config of the original
install. AFAIK grub is taken over by the new Ubuntu (flavour) install.
It most likely is possible to chose the original or the new install by
default, but assuming the OP should decide to remove the new install,
there's the need to manually fix grub after removing the new install.