diff -r 00f8d9f9920d -r d216e1c8b3fa test/min_cost_arborescence_test.cc
--- a/test/min_cost_arborescence_test.cc	Thu Sep 13 12:02:27 2012 +0200
+++ b/test/min_cost_arborescence_test.cc	Wed Nov 28 11:54:43 2012 +0100
@@ -91,6 +91,7 @@
   Arc e;
   VType c;
   bool b;
+  ignore_unused_variable_warning(c,b);
   int i;
   CostMap cost;
   ArbMap arb;