Packing

pacman

yaourt

PKGBUILD

# Set up chroot envirnment
pacman -S devtools
mkdir ~/chroot
CHROOT=$HOME/chroot
mkarchroot $CHROOT/root base base-devel

# Update packages in chroot
arch-nspawn $CHROOT/root pacman -Syu

# Run from the dir containing the PKGBUILD:
makechrootpkg -c -r $CHROOT

Build in Chroot

devtools