On a clean GNOME install from the Mageia-6-rc-x86_64-DVD ISO, after installing GNOME Tweak Tool, Tweak Tool shows a blank for the current GTK+ theme selection. When using the drop-drown list to select a GTL+ theme, the only option available is "High Contrast". If you select that, the theme changes correctly, but then there is no way to get back to the default Adwaita theme.
Installing the adwaita-gtk2-theme package fixes this. Should this get installed by default?
IIRC, we want to enforce Adwaita for GTK+2 on GNOME, so it should be installed by default. Assigning to the gnome@ maintainer group for confirmation and/or fix.