anchor.diff: -{ stdenv, fetchurl, gyp, utillinux }:
  +{ stdenv, fetchurl, gyp, utillinux, python }:
   
   let
     version = "2.1";
  
positive.code: 
    buildFlags = [ "BUILDTYPE=Release" ];
  
    buildInputs = [ gyp ] ++ stdenv.lib.optional stdenv.isLinux utillinux;
  
    doCheck = true;
  
    checkPhase = ''
      out/Release/test-nonstrict
  
negative.code:   '';
  
    installPhase = ''
      mkdir -p $out/lib
      mv out/Release/${if stdenv.isDarwin then "*.dylib" else "lib.target/*"} $out/lib
  
      mkdir -p $out/include
      mv http_parser.h $out/include
    '';
  
    postFixup = if stdenv.isDarwin then ''
      install_name_tool -id $out/lib/libhttp_parser.dylib $out/lib/libhttp_parser.dylib
      install_name_tool -id $out/lib/libhttp_parser_strict.dylib $out/lib/libhttp_parser_strict.dylib
    '' else null;
  
    meta = {
      description = "An HTTP message parser written in C";
  