anchor.diff:  
                                      # On GNU/Hurd glibc refers to Mach & Hurd
                                      # headers.
  -                                   ++ optionals (libcCross != null &&
  -                                                 hasAttr "propagatedBuildInputs" libcCross)
  +                                   ++ optionals (libcCross != null && libcCross ? "propagatedBuildInputs" )
                                           libcCross.propagatedBuildInputs)));
   
     LIBRARY_PATH = concatStrings
  
positive.code:   AR = "ar";
    LD = "ld";
    # http://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
    CC = if stdenv.system == "x86_64-solaris" then "gcc -m64"
         else "gcc";
  
    # Setting $CPATH and $LIBRARY_PATH to make sure both `gcc' and `xgcc' find
    # the library headers and binaries, regarless of the language being
  
negative.code:     else "install";
  
    crossAttrs = let
      xgccArch = stdenv.cross.gcc.arch or null;
      xgccCpu = stdenv.cross.gcc.cpu or null;
      xgccAbi = stdenv.cross.gcc.abi or null;
      xgccFpu = stdenv.cross.gcc.fpu or null;
      xgccFloat = stdenv.cross.gcc.float or null;
      xwithArch = if xgccArch != null then " --with-arch=${xgccArch}" else "";
      xwithCpu = if xgccCpu != null then " --with-cpu=${xgccCpu}" else "";
      xwithAbi = if xgccAbi != null then " --with-abi=${xgccAbi}" else "";
  