anchor.diff:    pythonPath = with pythonPackages;
       [ setuptools eventlet greenlet gflags netaddr sqlalchemy carrot routes
         paste_deploy m2crypto ipy boto_1_9 twisted sqlalchemy_migrate
  -      distutils_extra simplejson readline
  +      distutils_extra simplejson readline glance cheetah
  +      # !!! should libvirt be a build-time dependency?  Note that
  +      # libxml2Python is a dependency of libvirt.py. 
  +      libvirt libxml2Python 
       ];
   
     buildInputs =
       [ pythonPackages.python 
         pythonPackages.wrapPython
  +      pythonPackages.mox
         intltool
       ] ++ pythonPath;
   
  +  PYTHON_EGG_CACHE = "`pwd`/.egg-cache";
  +
     preConfigure =
       ''
  -      export HOME=$(pwd)
  -
         # Set the built-in state location to something sensible.
         sed -i nova/flags.py \
           -e "/DEFINE.*'state_path'/ s|../|/var/lib/nova|"
  
positive.code:       cp etc/nova-api.conf $out/etc/
      '';
  
    meta = {
      homepage = http://nova.openstack.org/;
      description = "OpenStack Compute (a.k.a. Nova), a cloud computing fabric controller";
  
negative.code: { stdenv, fetchurl, pythonPackages, intltool, libvirt, libxml2Python }:
  
  with stdenv.lib;
  
  