anchor.diff: -{ stdenv, fetchFromGitHub, readline, libedit, bc }:
  +{ stdenv, fetchFromGitHub, readline, libedit, bc
  +, avxSupport ? false
  +}:
   
   stdenv.mkDerivation rec {
     pname = "j";
  
positive.code:     patchShebangs .
      sed -i $JLIB/bin/profile.ijs -e "s@'/usr/share/j/.*'@'$out/share/j'@;"
  
      ./build_all.sh
  
      cp $SOURCE_DIR/bin/${platform}/j${bits}*/* "$JLIB/bin"
    '';
  
negative.code:     if stdenv.isLinux then "linux" else
      if stdenv.isDarwin then "darwin" else
      "unknown";
    variant = if stdenv.isx86_64 && avxSupport then "avx" else "";
  
    j64x="j${bits}${variant}";
  
    doCheck = true;
  
  