How to upgrade GTK 3.18 to 3.20 on ubuntu 16.04? [duplicate]

Solution 1:

If you Google this, you will find guides like this and this. In addition, you will find that this has been asked before on this very site at least twice: once in 2016 and once in 2015.

Now, to be fair, I'm used to arch, which already ships with 3.20. Being maybe 1 year after the release of 3.20, I almost didn't believe the Ubuntu guides above. Really? Add a separate repository, including one with staging in the name? Nevertheless, it's true and the tl;dr is very simple:

sudo add-apt-repository ppa:gnome3-team/gnome3-staging
sudo add-apt-repository ppa:gnome3-team/gnome3
sudo apt update
sudo apt dist-upgrade

I did these exact steps today, rebooted for good measure, and enjoyed that my preferred openbox themes (which work fine on arch) were no longer messed up (due to 3.18, which I never would have suspected).