anchor.diff:      downloadPage = "http://pari.math.u-bordeaux.fr/download.html";
       license     = licenses.gpl2Plus;
       maintainers = with maintainers; [ ertes raskin AndersonTorres ];
  -    platforms   = platforms.linux;
  +    platforms   = platforms.linux ++ platforms.darwin;
       updateWalker = true;
     };
   }
  
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:   buildInputs = [ gmp readline libX11 libpthreadstubs tex perl ];
  
    configureScript = "./Configure";
    configureFlags = [
      "--mt=pthread"
      "--with-gmp=${gmp.dev}"
      "--with-readline=${readline.dev}"
    ] ++ stdenv.lib.optional stdenv.isDarwin "--host=x86_64-darwin";
  
    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";
  