Deepin is not Ubuntu and ppa's are made for Ubuntu and their derivatives, I know there are a bunch of guides on "how to add ppa's to Debian" but they aren't officially supported on it or its derivatives. So if you install apps from ppa's on a Debian based distro, you can have a good install, a bad one or a complete disaster.
Been said that, if you still want to use last Mesa's version on Deepin and that ppa isn't working for you, go to the official page, download the .tar package and compile it (tedious and not less harmful work).

Thank's for replying, will try it on my next install.

Well unstable ppa's are made for testing and require some knowledge. We must prepare for a fresh install. Not the case of Oibaf PPA, it increases visual rendering.

I didn't say that because that thing, when you install an app it needs some dependencies, there is the possibility that the ones that the apps need come in discordance with the ones that some system part needs, the system is not isolated from being touched with apps you install.

Edited by alexwender at 2019-3-27 22:52

In "/etc/apt/sources.list" add:

deb http://http.debian.net/debian stretch-backports main contrib
You can choose the Debian Unstable repository... be careful not to "update everything" because Deepin will break if you continue.

dpkg --add-architecture i386

sudo apt update

sudo apt install libllvm6.0 libllvm6.0:i386

sudo apt install -t stretch-backports libegl1-mesa libegl1-mesa-dev libgl1-mesa-dri libgl1-mesa-dri:i386 libgl1-mesa-glx libgl1-mesa-glx:i386 libglapi-mesa libglapi-mesa:i386 libgles2-mesa libllvm5.0 libllvm5.0:i386

Remove the Debian repositories. And restart your computer.

These guidelines are not official. I found this tutorial on the internet... And it worked perfectly.