Comment 26 for bug 1723577

Daniel, sorry, I did not complete my post after #18 and apt policy result - we were discussing with didrocks and frenchy82 on the French forum with the details, I tried to resume here all steps in order other people and developers involved in bug also got the informations.

http://forum.ubuntu-fr.org/viewtopic.php?pid=21810017#p21810017

So I did (always in chroot mode) :
sudo dpkg -i libegl1-mesa_17.2.1-0ubuntu1_amd64.deb libgbm1_17.2.1-0ubuntu1_amd64.deb libgl1-mesa-dri_17.2.1-0ubuntu1_amd64.deb libgl1-mesa-glx_17.2.1-0ubuntu1_amd64.deb libglapi-mesa_17.2.1-0ubuntu1_amd64.deb libgles2-mesa_17.2.1-0ubuntu1_amd64.deb libwayland-egl1-mesa_17.2.1-0ubuntu1_amd64.deb libxatracker2_17.2.1-0ubuntu1_amd64.deb mesa-va-drivers_17.2.1-0ubuntu1_amd64.deb mesa-vdpau-drivers_17.2.1-0ubuntu1_amd64.deb

It downgraded the 10 packages installed in 17.2.1 version.

But when I rebooted normally, it was still frozen at Ubuntu screen and message 'Started User Manager for UID 121'

My graphic card : Gallium 0.4 on AMD CAPE VERDE (DRM 2.49.0 / 4.10.0-19-generic, LLVM 4.0.0)

After dpwngrading mesa, I tried downgrading mutter, xserver-xorg-video-ati, xorg-server, then booting on the grub to older kernels : nothing worked, I still have the bug on startup.

You're right, I don't know if I missed something on the instructions to come back on previous versions with the risk to eliminate the good direction to search, or if bug comes from something else...

I was afraid of that, but frenchy82 test seems to confirm downgrading mesa is not enough to solve the problem. I can continue to do some testings if you need.