anchor.diff:  
     # Work around a bug in the generated flex lexer (upstream flex bug?)
     NIX_CFLAGS_COMPILE = "-Wno-error";
  +
  +  postPatch = ''
  +    substituteInPlace ./configure --replace '/usr/share/fonts/unifont' '${unifont}/share/fonts'
  +  '';
   
     preConfigure =
       '' for i in "tests/util/"*.in
  
positive.code:            -e's/qemu-system-i386/qemu-system-x86_64 -nodefaults/g'
  
        unset CPP # setting CPP intereferes with dependency calculation
      '';
  
    prePatch =
      '' tar zxf ${po_src} grub-2.02~beta2/po
         rm -rf po
         mv grub-2.02~beta2/po po
         sh autogen.sh
         gunzip < "${unifont_bdf}" > "unifont.bdf"
         sed -i "configure" \
             -e "s|/usr/src/unifont.bdf|$PWD/unifont.bdf|g"
      '';
  
    patches = [ ./fix-bash-completion.patch ];
  
negative.code: stdenv.mkDerivation rec {
    name = "grub-${version}";
  
    src = fetchurl {
      url = "mirror://gnu/grub/${name}.tar.xz";
      sha256 = "03vvdfhdmf16121v7xs8is2krwnv15wpkhkf16a4yf8nsfc3f2w1";
    };
  
    nativeBuildInputs = [ bison flex python ];
    buildInputs = [ ncurses libusb freetype gettext devicemapper ]
      ++ optional doCheck qemu
      ++ optional zfsSupport zfs;
  