anchor.diff:            export GHC_PACKAGE_PATH=$PWD/dist/package.conf.inplace/:$GHC_PACKAGE_PATH
           '';
         });
  -      ghc-parser        = self.callCabal2nix "ghc-parser"     ghc-parser-src     {};
  +      ghc-parser        = self.callCabal2nix "ghc-parser" ghc-parser-src {};
         ipython-kernel    = self.callCabal2nix "ipython-kernel" ipython-kernel-src {};
  -      shelly = nixpkgs.haskell.lib.doJailbreak super.shelly;
  +      plot              = self.callCabal2nix "plot" plot {};
   
  -      plot              = self.callCabal2nix "plot"               plot             { inherit cairo pango; };
  +      shelly            = nixpkgs.haskell.lib.doJailbreak super.shelly;
  +      testing-feat      = nixpkgs.haskell.lib.doJailbreak super.testing-feat;
  +
  +      cairo             = nixpkgs.lib.overrideDerivation super.cairo (drv: {
  +        src = "${gtk2hs}/cairo";
  +      });
  +      glib              = nixpkgs.lib.overrideDerivation super.glib (drv: {
  +        src = "${gtk2hs}/glib";
  +      });
  +      pango             = nixpkgs.lib.overrideDerivation super.pango (drv: {
  +        src = "${gtk2hs}/pango";
  +      });
   
         Chart             = super.callHackage "Chart" "1.8.2" {};
         Chart-cairo       = super.callHackage "Chart-cairo" "1.8.2" {};
  -      cairo             = super.callHackage "cairo" "0.13.3.0" {};
         cubicbezier       = super.callHackage "cubicbezier" "0.6.0.4" {};
  -      diagrams          = super.callHackage "diagrams" "1.4" {};
  +      diagrams          = nixpkgs.haskell.lib.dontHaddock (super.callHackage "diagrams" "1.4" {});
         diagrams-cairo    = super.callHackage "diagrams-cairo" "1.4" {};
         diagrams-contrib  = super.callHackage "diagrams-contrib" "1.4.1" {};
         diagrams-core     = super.callHackage "diagrams-core" "1.4.0.1" {};
  
positive.code:     ihaskell
      ihaskell-aeson
      ihaskell-blaze
      # ihaskell-charts
      # ihaskell-diagrams
      ihaskell-gnuplot
      ihaskell-hatex
      ihaskell-juicypixels
  
negative.code:         "ihaskell-widgets"
        ]);
    haskellPackages = nixpkgs.haskell.packages.ghc821.override {
      overrides = self: super: {
        ihaskell       = nixpkgs.haskell.lib.overrideCabal (
                         self.callCabal2nix "ihaskell"          ihaskell-src       {}) (_drv: {
          postPatch = let
  