libvirt packages: fix & clean up dependencies

pkgs/applications/virtualization/virt-manager/default.nix

@@ -1,13 +1,13 @@
-{ stdenv, fetchurl, python2Packages, intltool, curl, file
-, wrapGAppsHook, virtinst, gtkvnc, vte
-, gtk3, gobjectIntrospection, libvirt-glib, gsettings_desktop_schemas, glib
-, avahi, dconf, spiceSupport ? true, spice_gtk, libosinfo, gnome3, system-libvirt
+{ stdenv, fetchurl, python2Packages, intltool, file
+, wrapGAppsHook, virtinst, gtkvnc, vte, avahi, dconf
+, gobjectIntrospection, libvirt-glib, system-libvirt
+, gsettings_desktop_schemas, glib, libosinfo, gnome3
+, spiceSupport ? true, spice_gtk ? null
 }:
 
 with stdenv.lib;
-with python2Packages;
 
-buildPythonApplication rec {
+python2Packages.buildPythonApplication rec {
   name = "virt-manager-${version}";
   version = "1.4.1";
   namePrefix = "";
@@ -17,17 +17,19 @@ buildPythonApplication rec {
     sha256 = "0i1rkxz730vw1nqghrp189jhhp53pw81k0h71hhxmyqlkyclkig6";
   };
 
-  propagatedBuildInputs =
-    [ eventlet greenlet gflags netaddr carrot routes
-      PasteDeploy m2crypto ipy twisted
-      distutils_extra simplejson glanceclient cheetah lockfile httplib2
-      urlgrabber virtinst pyGtkGlade dbus-python /*gnome_python FIXME*/ pygobject3
-      libvirt libxml2 ipaddr vte libosinfo gobjectIntrospection gtk3 mox
-      gtkvnc libvirt-glib glib gsettings_desktop_schemas gnome3.defaultIconTheme
-      wrapGAppsHook
+  nativeBuildInputs = [ wrapGAppsHook intltool file ];
+
+  buildInputs =
+    [ libvirt-glib vte virtinst dconf gtkvnc gnome3.defaultIconTheme avahi
+      gsettings_desktop_schemas libosinfo
     ] ++ optional spiceSupport spice_gtk;
 
-  buildInputs = [ dconf avahi intltool file ];
+  propagatedBuildInputs = with python2Packages;
+    [ eventlet greenlet gflags netaddr carrot routes PasteDeploy
+      m2crypto ipy twisted distutils_extra simplejson glanceclient
+      cheetah lockfile httplib2 urlgrabber pyGtkGlade dbus-python
+      pygobject3 ipaddr mox libvirt libxml2
+    ];
 
   patchPhase = ''
     sed -i 's|/usr/share/libvirt/cpu_map.xml|${system-libvirt}/share/libvirt/cpu_map.xml|g' virtinst/capabilities.py
@@ -35,7 +37,7 @@ buildPythonApplication rec {
   '';
 
   postConfigure = ''
-    ${python.interpreter} setup.py configure --prefix=$out
+    ${python2Packages.python.interpreter} setup.py configure --prefix=$out
   '';
 
   postInstall = ''