anchor.diff:            stage2Script
             ghc
             ghcHEAD
  -          ghc8_2_1
  +          ghc8_2
  +          ghc8_0
             ghc7
             ghc7_8
             ghcIosSimulator64
  
positive.code:       haskellOverlays.ghc-head
      ]);
    };
    ghc8_2_1 = (makeRecursivelyOverridable nixpkgs.haskell.packages.ghc821).override {
      overrides = lib.foldr lib.composeExtensions (_: _: {}) (let
        haskellOverlays = mkHaskellOverlays nixpkgs;
  
negative.code:       haskellOverlays.ghc-8_2_1
      ]);
    };
    ghc = ghc8_0;
    ghc8_0 = (makeRecursivelyOverridable nixpkgs.haskell.packages.ghc802).override {
      overrides = lib.foldr lib.composeExtensions (_: _: {}) (let
        haskellOverlays = mkHaskellOverlays nixpkgs;
      in [
  