overlay.nix

  grahamc = {
    guis = self.buildEnv {
      name = "grahams-guis";
      pathsToLink = [ "/bin" ];
      extraOutputsToInstall = [ "bin" ];
      paths = with self; [
        (self.grahamc.pick firefox "bin/firefox")
        google-chrome

        (self.grahamc.pick custom-emacs "bin/emacs")
        (self.grahamc.pick pavucontrol "bin/pavucontrol")
        slack
      ];
    };

    pick = src: path: self.runCommand "picked" {} ''
      mkdir -p "$(dirname "$out/${path}")"
      ln -s "${src}/${path}" "$out/${path}"
    '';
  };