If the package's root directory is not chmod 755 then it is changed
to chmod 755; the package is built and the original permissions of the
directory are restored.  There's probably not much call for changing the
permissions back to what they were previously, as once makepkg has
trampled over the directory, it's pretty much trashed anyway
(at least if you convert symlinks), but I chose to revert the permissions
just incase the directory contains important files and the build dir is
in an area where others may see it.