self: super:

{
  # Install overlay:
  # > mkdir -p .config/nixpkgs/overlays
  # # use ? to avoid caching
  # > curl -L "https://gist.github.com/tbenst/0e2c7bd0219eda87e3915182071f224b/raw?$(date +%s%N)" -o ~/.config/nixpkgs/overlays/tb.nix
  # > nix-env -f '<nixpkgs>' -r -iA userPackages
  userPackages = super.userPackages or {} // {
    hello = self.hello;
    nix = self.nix;
    hexchat = self.hexchat;
    fzf = self.fzf;
    ripgrep = self.ripgrep;
    atom = self.atom;

    nix-rebuild = super.writeScriptBin "nix-rebuild"
      ''
        #!${super.stdenv.shell}
        curl -L "https://gist.github.com/tbenst/0e2c7bd0219eda87e3915182071f224b/raw?$(date +%s%N)" -o ~/.config/nixpkgs/overlays/tb.nix
        exec nix-env -f '<nixpkgs>' -r -iA userPackages "$@"
      '';
  };
}