anchor.diff:                      pkgs.grpcio-tools
                     ]);
   
  -                in rec {
  +                in {
                     configureFlags = (oldDerivation.configureFlags or []) ++ [
                       "--flags=with-examples"
                     ];
   
  -                  buildDepends = [
  +                  buildDepends = (oldDerivation.buildDepends or [ ]) ++ [
                       pkgsNew.makeWrapper
                       # Give our nix-shell its own cabal so we don't pick up one
                       # from the user's environment by accident.
  
positive.code:                 })
              );
  
          parameterized = pkgsNew.haskell.lib.appendPatch haskellPackagesOld.parameterized ./nix/parameterized.patch;
  
        };
      };
  
negative.code: #     };);
  
  let
    overlay = pkgsNew: pkgsOld: {
  
      grpc = pkgsNew.callPackage ./nix/grpc.nix { };
  
      haskellPackages = pkgsOld.haskellPackages.override {
        overrides = haskellPackagesNew: haskellPackagesOld: rec {
          parameterized =
            pkgsNew.haskell.lib.overrideCabal
            haskellPackagesOld.parameterized
            (old: {
              broken = false;
              patches = (old.patches or [ ]) ++ [ ./nix/parameterized.patch ];
            });
  
          haskell-src =
            haskellPackagesNew.callHackage "haskell-src" "1.0.3.1" {};
  