The second idea is that this advice should prevent the script from *accidentally* damage my system. But this could be prevented by using fakeroot (which is disabled when calling makepkg with --asroot according to the
manpage) or chroot. And actually the proper advice in this case should be to execute makepkg using a user dedicated for this, as for most arch users it would be worse if their personal file get deleted as if the system becomes unbootable. I agree. A good idea is to automatically change to a much more restricted user, used just for building (no shells, logins, etc.). Chroot is too much of a hassle with, most of times, no point. You'll have to deal with dependent libs etc. etc. etc. A good option here could be to hardlink/copy the files of the dependencies inside the chroot temporary in order to do the job. But still, I think it's too much. You should check the scripts on your own...