anchor.diff:    ghc = ghc8_0;
     ghc8_0 = (makeRecursivelyOverridable nixpkgs.haskell.packages.ghc802).override {
       overrides = lib.foldr lib.composeExtensions (_: _: {}) (let
  -      haskellOverlays = mkHaskellOverlays nixpkgs;
  +      haskellOverlays = nixpkgs.haskell.overlays;
       in [
         haskellOverlays.reflexPackages
         haskellOverlays.untriaged
  
positive.code:   };
    ghc7 = (makeRecursivelyOverridable nixpkgs.haskell.packages.ghc7103).override {
      overrides = lib.foldr lib.composeExtensions (_: _: {}) (let
        haskellOverlays = mkHaskellOverlays nixpkgs;
      in [
        haskellOverlays.reflexPackages
        haskellOverlays.untriaged
  
negative.code:   ghc8_2 = ghc8_2_1;
    ghc8_2_1 = (makeRecursivelyOverridable nixpkgs.haskell.packages.ghc821).override {
      overrides = lib.foldr lib.composeExtensions (_: _: {}) (let
        haskellOverlays = nixpkgs.haskell.overlays;
      in [
        haskellOverlays.reflexPackages
        haskellOverlays.untriaged
  