Even if this means that Ubuntu GNOME need to ship the numix-gtk-theme version which supports GNOME 3.20 through the gnome3-staging PPA, it really should be done for as you can see here, the Numix version for Ubuntu GNOME 16.04 does not support GNOME 3.20: https://github.com/numixproject/numix-gtk-theme/issues/469
Even if this means that Ubuntu GNOME need to ship the numix-gtk-theme version which supports GNOME 3.20 through the gnome3-staging PPA, it really should be done for as you can see here, the Numix version for Ubuntu GNOME 16.04 does not support GNOME 3.20: https:/ /github. com/numixprojec t/numix- gtk-theme/ issues/ 469