xfsprog and grub
Simon Quigley advises on an issue with xfsprog and grub:
xfsprogs enabled several features by default which are incompatible with the
latest version of GRUB. You have to either revert this patch in xfsprogs, or
use a snapshot version of GRUB, and for Ubuntu the only option really is the
former. Lots of Arch distros are doing the latter.
Could we potentially disable those flags by default in kpmcore so Calamares
and KDE Partition Manager users don't face this issue themselves? I will be
happy to send some code upstream, otherwise I know you know how to find the
xfsprogs fix in Ubuntu... ;)