xconfig --startxonboot --defaultdesktop=GNOME # Start the display session on boot. Although it says --startx, which seems to imply xorg, it is actually generic and thus works also with Wayland.
%packages --exclude-weakdeps # Beginning of the packages section. Excludes weak package dependencies
gnome-shell # the version 3 of the GNOME desktop environment, without any presintalled applications
gnome-terminal # install the default terminal for GNOME Shell
-gnome-tour # delete GNOME Tour so it doesn't automatically launch on boot
dejavu-sans-mono-fonts # the gnome-shell package doesn't include much fonts by default, resulting in weird spacings in GNOME Terminal. GNOME Terminal unfortunately doesn't automatically pick this font
elementary-wallpapers-gnome.noarch # Gorgeous wallpapers from the elementary OS project
wpa_supplicant # WPA Supplicant for Linux. It is not packaged by default in gnome-shell, but necessary to configure wireless networks using the Network Manager
%post --nochroot --log=/mnt/sysimage/opt/base-desktop-gnome.log # Beginning of %post section. Those commands are executed outside the chroot environment