{
  nixpkgs = {
    kb = builtins.fetchGit {
      url = "https://github.com/kennyballou/nixpkgs.git";
      ref = "override-erlang-emacs-mode";
      rev = "a730bb1666e7614071a0c7b1ed4dac5ba5d03753";
    };
    unstable = builtins.fetchGit {
      url = "https://github.com/NixOS/nixpkgs.git";
      rev = "32356ce11b8cc5cc421b68138ae8c730cc8ad4a2";
    };
    stable = builtins.fetchGit {
      url = "https://github.com/NixOS/nixpkgs.git";
      rev = "47b35f569e84eb6dbbcf0a9fc75d8729ab8837fd";
    };
  };
  home-manager = builtins.fetchGit {
    url = "https://github.com/nix-community/home-manager.git";
    rev = "c751aeb19e84a0a777f36fd5ea73482a066bb406";
  };
  emacs-overlay = {
    master = builtins.fetchTarball {
      url = "https://github.com/nix-community/emacs-overlay/archive/master.tar.gz";
    };
    stable = builtins.fetchGit {
      url = "https://github.com/nix-community/emacs-overlay.git";
      rev = "1d86b8a65cc68b9f71c1821d8d81ab16d19a31b0";
    };
  };
}