Nix overlay to override system compiler

cc.nix

(self: super:
  let
    stdenv = let stdenv = super.overrideCC super.stdenv super.gcc8; in
             stdenv.override { cc = super.stdenv.cc; };
  in {
    inherit stdenv;
  })
  #   stdenv = gcc8Stdenv.override {
  #   cc = gcc8Stdenv.override {
  #     inherit (self) libc;
  #     bintools = if super.stdenv.cc.bintools ? override then
  #       (super.stdenv.cc.bintools.override {
  #         inherit (self) libc;
  #       }) else super.stdenv.cc.bintools;
  #   };
  # };