Just curious, why do you install packer to install yaourt? Aren't they equivalent?
@ektick - I've had luck with running following to fix that problem.
pacman -Sy archlinux-keyring
base-devel fails to install when I am trying to rebuild this image from base/arch. Comes up with errors "Import PGP ey 4096R/, ... error: key could not be imported. I suspect base/arch is out-of-date and needs to be rebuilt.
base-devel is not really installed