anchor.diff:    buildInputs = [ gmp readline libX11 libpthreadstubs tex perl ];
   
     configureScript = "./Configure";
  -  configureFlags =
  -    "--mt=pthread" +
  -    "--with-gmp=${gmp.dev} " +
  -    "--with-readline=${readline.dev}";
  +  configureFlags = [
  +    "--mt=pthread"
  +    "--with-gmp=${gmp.dev}"
  +    "--with-readline=${readline.dev}"
  +  ] ++ stdenv.lib.optional stdenv.isDarwin "--host=x86_64-darwin";
   
  -  makeFlags = "all";
  +  preConfigure = ''
  +    export LD=$CC
  +  '';
  +
  +  postConfigure = stdenv.lib.optionalString stdenv.isDarwin ''
  +    echo 'echo x86_64-darwin' > config/arch-osname
  +  '';
  +
  +  makeFlags = [ "all" ];
   
     meta = with stdenv.lib; {
       description = "Computer algebra system for high-performance number theory computations";
  
positive.code:        Bordeaux I, France), PARI is now under the GPL and maintained by Karim
         Belabas with the help of many volunteer contributors.
  
         - PARI is a C library, allowing fast computations.  
         - gp is an easy-to-use interactive shell giving access to the
            PARI functions.
         - GP is the name of gp's scripting language.
         - gp2c, the GP-to-C compiler, combines the best of both worlds 
            by compiling GP scripts to the C language and transparently loading 
            the resulting functions into gp. (gp2c-compiled scripts will typically
            run 3 or 4 times faster.) gp2c currently only understands a subset
             of the GP language.
  
negative.code:     downloadPage = "http://pari.math.u-bordeaux.fr/download.html";
      license     = licenses.gpl2Plus;
      maintainers = with maintainers; [ ertes raskin AndersonTorres ];
      platforms   = platforms.linux ++ platforms.darwin;
      updateWalker = true;
    };
  }
  