Sorry, minor typo. It should be fixed. How is the PKGBUILD broken? It works fine for me.
It will probably work if you have a local clone of the repo and just do a makepkg therein.
If you look at it like the average user that tries to build a package, it works only when you already cloned the repo, so you have to comment out the _hgrepo and _hgroot lines on the first run, but then this "ln -snf" does not work, because the path exists, and then "cd $startdir" further below should read "cd $startdir/src/wmii" (or better "cd $srcdir/wmii" according to the Arch guidelines).
-- Thomas Dahms