anchor.diff:  
   with stdenv.lib;
   let
  -  version = "2.6.1";
  +  version = "2.7.0";
     audio = optionalString (hasSuffix "linux" stdenv.system) "alsa,"
       + optionalString pulseSupport "pa,"
       + optionalString sdlSupport "sdl,";
  
positive.code: 
    src = fetchurl {
      url = "http://wiki.qemu.org/download/qemu-${version}.tar.bz2";
      sha256 = "1l88iqk0swqccrnjwczgl9arqsvy77bis862zxajy7z3dqdzshj9";
    };
  
    buildInputs =
  
negative.code: 
    patches = [
      ./no-etc-install.patch
    ];
    hardeningDisable = [ "stackprotector" ];
  
    configureFlags =
      [ "--smbd=smbd" # use `smbd' from $PATH
  