nix livecd with "blocks" support for in-place bcache addition

iso.nix

{config, pkgs, lib, ...}:
let
  maintboot =  pkgs.python3Packages.buildPythonPackage rec {
    pname = "maintboot";
    version = "1";
    src = pkgs.fetchFromGitHub {
      owner = "g2p";
      repo = "maintboot";
      rev = "1c5ab872bae2b69a06252ca2e7ecdba4d4ad8e57";
      sha256 = "0n8sy6ksqb5s1n5qqshb6pz1d86gjshwb30mr1nil0hfln5gi4g2";
    };
  };
  blocks = pkgs.python3Packages.buildPythonApplication rec {
    name = "blocks";
    version = "0.1.4";
    checkInputs = [ maintboot
		    pkgs.python3Packages.augeas
		    pkgs.python3Packages.pyparted ];
    src = pkgs.fetchFromGitHub {
      owner = "g2p";
      repo = "blocks";
      rev = "d00d8aa2bcb64ef511";
      sha256 = "12h5h1kdwbn92w3qj4m9wnvdiarc9mwdkwjx09dvj3af2rnvpz29";
    };
  }; in
{
  imports = [
    <nixpkgs/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix>

    # Provide an initial copy of the NixOS channel so that the user
    # doesn't need to run "nix-channel --update" first.
    <nixpkgs/nixos/modules/installer/cd-dvd/channel.nix>
  ];
  environment.systemPackages = [blocks] ++ (with pkgs; [ bcache-tools ]);
}