Trying Lakka on an old PC for the first time (6600k / 1060 6gb)
I tried 64-bit PC with AMD/Intel/nVidia GPU (X.org) (/x11.x86_64/Lakka-x11.x86_64-6.1.img.gz) and i get
failed to start xorg.service
failed windowmanager.service
failed to start retroarch.service
After install 
Cheers 
We are using for Xorg Nvidia driver version 590.48.01 which has dropped support for Pascal GPU.
You can make a test with GBM version which should work with the Nouveau driver but the performance won’t be on par with the Nvidia driver.
It is better to have AMD GPU (or Intel) which have good support with the open source driver on Linux.