pkguser also for hardened gentoo?

[piotr5]

Matthias Benkmann had a strange idea: build each package not as root but as a user with the username matching the package-name. a great idea for linuxfromscratch where without a distro you have full responsibility for the system's security. during compilation and installation in the usual way the build-system gets full access to the filesystem, often overwriting files or changing permissions in installation. in gentoo this is no problem, the installation happens into a directory and not into the rootfs. another reason against pkguser is that security in the kernel goes into the direction where some programs will only execute when they are owned by root. nonetheless I think on a hardened gentoo emerge and portage shouldn't get root privilegues, who knows what worms and spy-software has been smuggled into the build-scripts or portage itself. and if such a breakage would be detected, it is impossible to figure out where it came from. additionally some filesystems don't support acl and user-privilegues might be an interesting alternative. and finally there is the question how much you trust your distro. should root actually be given to computer-programs or should it rather be a privilegue of admins only? fact is if you emerge all your packages with whatever other username, the vulneribility still is with that other user, such a user would then have access to all installed files on this computer. also interesting perspective is to restrict read-access to config-files only to the programs that require reading them. seen abstractly every open-source program installed is alike to one user (the programmer-team) getting access to your computer. would you grant root access to so many people?

https://github.com/JohnBurrell/LFS-BuildScripts for the current version.
http://www.linuxfromscratch.org/hints/downloads/files/more_control_and_pkg_man.txt the description from the author
http://wiki.linuxfromscratch.org/hints/browser/trunk/PREVIOUS_FORMAT/more_control_and_pkg_man.txt?rev=904 a version including an su-replacement.

so, what do you think? is pkguser overkill for gentoo security? you have any other solutions for the problems I pointed out? well, my favourite solution is to unmount rootfs before installation, I just am not sure how to do that...