NixOS configuration files for a persistant USB install and a virtualbox VM.
I just make a symlink:
cd /etc/nixos
git clone http://bugs.sleepanarchy.com/nixos-config.git
ln -s nixos-config/nexus_vm.nix configuration.nix
But if you want to override some options, you could include a file into in your
own configuration.nix:
imports = [
./nixos-config/common.nix
];
boot.loader.grub.version = 1;
. . .