anchor.diff:    installPhase = ''
       mkdir -p $out/bin
       mv chromedriver $out/bin
  -    patchelf --set-interpreter ${glibc.out}/lib/ld-linux-x86-64.so.2 $out/bin/chromedriver
  -    wrapProgram "$out/bin/chromedriver" \
  -      --prefix LD_LIBRARY_PATH : "${stdenv.lib.makeLibraryPath [ stdenv.cc.cc.lib cairo fontconfig freetype gdk_pixbuf glib gtk2 libX11 nspr nss pango libXrender gconf libXext libXi ]}:\$LD_LIBRARY_PATH"
  +    ${lib.optionalString (!stdenv.isDarwin) "patchelf --set-interpreter ${glibc.out}/lib/ld-linux-x86-64.so.2 $out/bin/chromedriver"}
  +    ${lib.optionalString (!stdenv.isDarwin) ''wrapProgram "$out/bin/chromedriver" \
  +      --prefix LD_LIBRARY_PATH : "${stdenv.lib.makeLibraryPath [ stdenv.cc.cc.lib cairo fontconfig freetype gdk_pixbuf glib gtk2 libX11 nspr nss pango libXrender gconf libXext libXi ]}:\$LD_LIBRARY_PATH"''}
     '';
   
     meta = with stdenv.lib; {
  
positive.code:     description = "A WebDriver server for running Selenium tests on Chrome";
      license = licenses.bsd3;
      maintainers = [ maintainers.goibhniu ];
      platforms = platforms.linux;
    };
  }
  
negative.code: { stdenv, fetchurl, cairo, fontconfig, freetype, gdk_pixbuf, glib
  , glibc, gtk2, libX11, makeWrapper, nspr, nss, pango, unzip, gconf
  , libXi, libXrender, libXext, lib
  }:
  let
    spec = if stdenv.system == "i686-linux" then { system="linux32"; sha256="5d267a8d59f18f1134966e312997b75976f8d816318b5b79b8357a3ac2c022da"; }
      else if stdenv.system == "x86_64-linux" then { system="linux64"; sha256="d011749e76305b5591b5500897939b33fac460d705d9815b8c03c53b0e1ecc7c"; }
      else if stdenv.system == "x86_64-darwin" then { system="mac64"; sha256="e95fb36ab85264e16c51d58dd9766624eca6b6339569da0460088f4c788c67ad"; }
      else abort "missing chromedriver binary for ${stdenv.system}";
  in
  stdenv.mkDerivation rec {
    name = "chromedriver-${version}";
    version = "2.25";
  
    src = fetchurl {
      url = "http://chromedriver.storage.googleapis.com/${version}/chromedriver_${spec.system}.zip";
      sha256 = spec.sha256;
    };
  
    buildInputs = [ unzip makeWrapper ];
  