shell.nix

let
  np = import <nixpkgs> {};
  myEmacsConfig = np.writeText "default.el" ''
;; initialize package

(require 'package)
(package-initialize 'noactivate)

;; load some packages

(require 'cedille-mode)
    '';
    myEmacs = np.emacsWithPackages (epkgs: (with epkgs; [
      (np.runCommand "default.el" {} ''
mkdir -p $out/share/emacs/site-lisp
cp ${myEmacsConfig} $out/share/emacs/site-lisp/default.el
'')
      np.emacsPackages.cedille
      melpaStablePackages.use-package
    ]));
in
  np.mkShell { buildInputs = [ myEmacs ];}