anchor.diff:          # See: https://github.com/snapframework/heist/pull/111
           heist = dontCheck (doJailbreak super.heist);
           hasktags = dontCheck super.hasktags;
  +
  +        # Allow newer vinyl package.
  +        composite-base = doJailbreak super.composite-base;
  +        composite-aeson = doJailbreak super.composite-aeson;
  +
  +        # Vinyl 0.8.x
  +        vinyl = with self; haskellPackages.mkDerivation {
  +          pname = "vinyl";
  +          version = "0.8.1.1";
  +          src = fetchgit {
  +            url = "https://github.com/VinylRecords/Vinyl.git";
  +            rev = "0917b5bed57428be6609ad030cbb3244b39b52ea";
  +            sha256 = "0jrqa0dzhd3bxv3sp4n1xhs63wn4gd0izy679jasni1wwa7zrbmf";
  +          };
  +          libraryHaskellDepends = [ array base ghc-prim ];
  +          testHaskellDepends = [
  +            base doctest hspec lens microlens should-not-typecheck singletons
  +          ];
  +          benchmarkHaskellDepends = [
  +            base criterion linear microlens mwc-random primitive tagged vector
  +          ];
  +          description = "Extensible Records";
  +          license = stdenv.lib.licenses.mit;
  +        };
         };
       };
   
  
positive.code:       safe
        scotty
        shakespeare
        snap
        snap-loader-static
        snap-templates
  
negative.code:       unordered-containers
        uuid
        vector
        vinyl
        wai-websockets
        websockets
        wreq
  