anchor.diff:      # Rename needed libraries and binaries, fix interpreter
       lib.optionalString stdenv.isLinux ''
         find . -type f -perm -0100 -exec patchelf \
  -          --replace-needed libncurses${lib.optionalString stdenv.is64bit "w"}.so.6 libncurses.so \
             --interpreter ${glibcDynLinker} {} \;
   
         sed -i "s|/usr/bin/perl|perl\x00        |" ghc-${version}/ghc/stage2/build/tmp/ghc-stage2
  
positive.code: { lib, stdenv
  , fetchurl, perl, gcc
  , ncurses6, gmp, glibc, libiconv, numactl
  , llvmPackages
  
  
negative.code:   useLLVM = !stdenv.targetPlatform.isx86;
  
    libPath = lib.makeLibraryPath ([
      # The i686-linux bindist provided by GHC HQ is currently built on Debian 9,
      # which link it against `libtinfo.so.5` (ncurses 5).
      # Other bindists are linked `libtinfo.so.6` (ncurses 6).
      (if stdenv.hostPlatform.system == "i686-linux" then ncurses5 else ncurses6)
      gmp
    ] ++ lib.optional (stdenv.hostPlatform.isDarwin) libiconv
      ++ lib.optional (stdenv.hostPlatform.isAarch64) numactl);
  
  