@ rigelk
i was enable to reproduce the issue (i did a test). All seem working fine. but...
A distinction need to be precised. Makepkg do not install anything, makepkg only compile the package. The installation is made by pacman. Makepkg need user privilegies, pacman need root privilegies.
Well, i think you logged on with root and try to install the system, right?So, the installer try to find the SUDO_OWNER when it need to compile the package and if you logged on with root, it find root as owner and, obviously it cannot build the package.
You must log on with user privilegies ( obarun as user for the LIVE ISO).
So, log on with obarun user as speudo and toor as password, then update the script:
$ sudo pacman -Sy obarun-install
now launch it with sudo :
$ sudo obarun-install
it should install the thing correctly
If the trouble persist, please tell me it