I was installing a package from aur today (with yaourt), when i ran out of space in my /tmp partition. the computer is a 901 eee-pc runnig arch linux. the /tmp partition as only 60MB in size so its prone to kind of situation i guess. what it happened was that i ran out of space while building the package.

to solve the problem decided to manually build the package. the solution was to copy the entire yaourt tmp dir (/tmp/yaourt***something) to my home dir and continue the process from there with the command:

$makepkg PKGBUILD

this step will build a compressed package *.pkg.tar.xz.

to install simply did (as root):

#pacman -U package_name.pkg.tar.xz

more info on pkgbuild here