I would like to see the output of
pacman -Qs optimus
pacman -Qs nvidia
pacman -Qs vala
EDIT - you mentioned it … optimus manager. Knew it.
So … do you really need it ? Do you realize it is an AUR package that needs to be rebuilt?
IF you need it … you need to rebuild it against your current libraries, as you would with other AUR packages.
But thats if … most who use optimus manager actually have no reason to.
I would suggest removing it altogether … but one way or the other, it is likely the source of your issue.
See here: