Comment 10 for bug 1726545

And in Ubuntu 19.04. This is getting old. Maybe wayland should relent from their purist stance (after all Unix always allowed root to do absolutely anything to the file system, and that's the keys to the kingdom). Maybe Ubuntu should accept the workaround GParted implements.
But neither side wants to compromise their principals, resulting in a system that's not self-consistent.

Meantime, I've implemented a SUDO wrapper that works for Gparted and other GUI apps, as advised by https://wiki.archlinux.org/index.php/Running_GUI_applications_as_root#Using_xhost