Thanks, David, but after editing /usr/share/applications/org.buddiesofbudgie.BudgiePolkit.desktop, xhost now outputs this error message:
xhost +x
xhost: bad hostname “x”
However I solved the problem by modifying one of my aliases:
alias sgp=‘xhost si:localuser:root; sudo gparted 2> /dev/null’ # Launch Gparted in “sudo” mode
And I took the opportunity to create a universal alias that allows you to launch any application in “sudo” mode:
alias sd=‘_sd() { xhost si:localuser:root; sudo “$1” “$2” 2> /dev/null; }; _sd’ # Launch a graphical application in “sudo” mode
sd gparted
sd nemo /usr/share/applications
sd gedit /etc/fstab
For more information about the method, see this topic.