Use this PKGBUILD to build and install RimWorld alpha 11. You need to have
your own copy of RimWorld. If you don't already have a copy of RimWorld, you
can grab one here: http://rimworldgame.com/.
# clone the repo
git clone https://github.com/njurgens/rimworld-pkgbuild.git
# copy the RimWorld zip file into the same directory as the `PKGBUILD`.
cp /path/to/RimWorldAlpha11.zip rimworld-pkgbuild/
# run makepkg to build and install
cd rimworld-pkgbuild
makepkg --install