iso-image.nix contains the minimal stuff necessary to build a
bootable ISO image containing the given configuration. The idea is
that this can be customised by providing additional modules, e.g. to
add extra packages to the image.
The ISO image is exported in the configuration attribute
system.build.isoImage. So it can be built as follows:
$ nix-build lib/eval-config.nix \
--arg configuration 'import ./modules/installer/cd-dvd/iso-image.nix' \
-A config.system.build.isoImage
svn path=/nixos/branches/modular-nixos/; revision=15871