Oops, forgot to update Arch linux for a while and was met by the following message after trying to run
error: failed to prepare transaction (could not satisfy dependencies) :: package-query: requires pacman<4.3
This is because there was a change in the library that bridged between yaourt and pacman.
To fix, remove package-query and manually install the snapshot from AUR:
pacman -Rdd package-query git clone https://aur.archlinux.org/package-query.git cd package-query makepkg -si
You should now be clear to run