anchor.diff:              sha256 = "6297433ee120b11b4b0a1c8f3512d7d73501753142ab9e2daa13c5a3edd32a72";
           })
           (fetchurl {
  -            url = "mirror://gnu/gcc/gcc-${gcc_version}/gcc-${gcc_version}.tar.bz2";
  -            sha256 = "f06ae7f3f790fbf0f018f6d40e844451e6bc3b7bc96e128e63b09825c1f8b29f";
  +            url = "mirror://gnu/gcc/gcc-${gcc_version}/gcc-${gcc_version}.tar.xz";
  +            sha256 = "850bf21eafdfe5cd5f6827148184c08c4a0852a37ccf36ce69855334d2c914d4";
           })
           (fetchurl {
               url = "ftp://sourceware.org/pub/newlib/newlib-${newlib_version}.tar.gz";
  
positive.code:     sourceRoot = ".";
      
      nativeBuildInputs = [ texinfo bison flex ];
      buildInputs = [ gmp mpfr libmpc isl_0_11 cloog_0_18_0 zlib libelf ];
      
      hardeningDisable = [ "format" ];
      
  
negative.code: # This was written partly based on https://github.com/EliasOenal/TNT,
  # and the patches were also taken from there.
  
  { stdenv, fetchurl, gmp, mpfr, libmpc, isl
  , zlib, libelf, texinfo, bison, flex
  , optimizeForSize ? false
  }:
  let
      gcc_version = "6.4.0";
      binutils_version = "2.28";
      newlib_version = "2.5.0.20170421";
      
  