For nvidia-390xx-dkms users
The AUR package nvidia-390xx-dkms is not yet updated for kernel 5.8. If you have an older Nvidia card that needs the 390 driver, wait until the AUR package gets updated (hopefully in a few days), or your system will be unbootable.
Also, a good idea is to install linux-lts kernel, just so you can boot in case you do update.
EDIT: It’s okay to update now.
The driver in the AUR has been updated, everything works fine. 