anchor.diff:  { stdenv, fetchurl, which, zlib, pkgconfig, SDL, openssl, python
   , libuuid, gettext, ncurses, dev86, iasl, pciutils, bzip2, xz
  -, lvm2, utillinux, procps }:
  +, lvm2, utillinux, procps, texinfo }:
   
  -let version = "4.0.1"; in 
  +with stdenv.lib;
  +
  +let
  +
  +  version = "4.0.1";
  +
  +  # Sources needed to build the stubdoms.
  +
  +  stubdomSrcs =
  +    [ { url = http://xenbits.xensource.com/xen-extfiles/lwip-1.3.0.tar.gz;
  +        sha256 = "13wlr85s1hnvia6a698qpryyy12lvmqw0a05xmjnd0h71ralsbkp";
  +      }
  +      { url = http://xenbits.xensource.com/xen-extfiles/zlib-1.2.3.tar.gz;
  +        sha256 = "0pmh8kifb6sfkqfxc23wqp3f2wzk69sl80yz7w8p8cd4cz8cg58p";
  +      }
  +      { url = http://xenbits.xensource.com/xen-extfiles/newlib-1.16.0.tar.gz;
  +        sha256 = "01rxk9js833mwadq92jx0flvk9jyjrnwrq93j39c2j2wjsa66hnv";
  +      }
  +      { url = http://xenbits.xensource.com/xen-extfiles/grub-0.97.tar.gz;
  +        sha256 = "02r6b52r0nsp6ryqfiqchnl7r1d9smm80sqx24494gmx5p8ia7af";
  +      }
  +      { url = http://xenbits.xensource.com/xen-extfiles/pciutils-2.2.9.tar.bz2;
  +        sha256 = "092v4q478i1gc7f3s2wz6p4xlf1wb4gs5shbkn21vnnmzcffc2pn";
  +      }
  +    ];
  +
  +in 
   
   stdenv.mkDerivation {
     name = "xen-${version}";
  
positive.code:   meta = {
      homepage = http://www.xen.org/;
      description = "Xen hypervisor and management tools for Dom0";
    };
  }
  
negative.code: 
    buildInputs =
      [ which zlib pkgconfig SDL openssl python libuuid gettext ncurses
        dev86 iasl pciutils bzip2 xz texinfo
      ];
  
    makeFlags = "PREFIX=$(out) CONFIG_DIR=/etc";
  
    buildFlags = "xen tools stubdom";
  
    preBuild =
      ''
  