You need to install the kernel headers, first:
sudo pacman -S $(pacman -Qsq "^linux" | grep "^linux[0-9]*[-rt]*$" | awk '{print $1"-headers"}' ORS=' ')
You need to install the kernel headers, first:
sudo pacman -S $(pacman -Qsq "^linux" | grep "^linux[0-9]*[-rt]*$" | awk '{print $1"-headers"}' ORS=' ')