anchor.diff:  
     ihaskell = callPackage ../development/tools/haskell/ihaskell/wrapper.nix {
       inherit (pythonPackages) ipython;
  -    inherit (haskellngPackages) ihaskell ghcWithPackages;
  +    inherit (haskellPackages) ihaskell ghcWithPackages;
       packages = config.ihaskell.packages or (self: []);
     };
   
  
positive.code:   agda = callPackage ../build-support/agda {
      glibcLocales = if pkgs.stdenv.isLinux then pkgs.glibcLocales else null;
      extension = self : super : { };
      inherit (haskell-ng.packages.ghc784) Agda;
      inherit writeScriptBin;
    };
  
  
negative.code: 
      external = {
        # FIXME: revert when Agda and ghc-mod are fixed on 7.10
        inherit (haskell.packages.ghc784) ghc-mod Agda;
        inherit (haskellPackages) structured-haskell-mode;
      };
    };
  
  