In this exemple, we are talking about Nvidia drivers with both open and proprietary models precompiled in dkms /var/lib.
For this to work, it is needed to install both drivers in different dirs and rename for open version:
- /var/lib/dkms/nvidia
- /var/lib/dkms/open-nvidia
To prevent auto install of proprietary driver at kernel update overwriting open-nvidia, the config empty files /etc/dkms/no-autoinstall is mandatory, and the option AUTOINSTALL=yes is set in the dkms conf file of the current used driver and unset in the unused.
DKMS 3.1.4 doesn't recognize or take care of no-autoinstall file and return weird variables values line 'standard_output' during compilation and finally breaks with "fatal error" concluding with a crash of the xserver.
Downgrading to 3.0.13 solved the problem.