expand_new_virtuals: handle None for myuse
diff --git a/pym/portage/dep/dep_check.py b/pym/portage/dep/dep_check.py
index 9373ecb..ca65601 100644
--- a/pym/portage/dep/dep_check.py
+++ b/pym/portage/dep/dep_check.py
@@ -125,7 +125,11 @@
 				virt_atom += str(x.unevaluated_atom.use)
 				virt_atom = Atom(virt_atom)
 				if graph_parent is None:
-					virt_atom = virt_atom.evaluate_conditionals(myuse)
+					if myuse is None:
+						virt_atom = virt_atom.evaluate_conditionals(
+							mysettings.get("PORTAGE_USE", "").split())
+					else:
+						virt_atom = virt_atom.evaluate_conditionals(myuse)
 				else:
 					virt_atom = virt_atom.evaluate_conditionals(
 						pkg_use_enabled(graph_parent))