Index: src/InitTweak/FixInit.cc
===================================================================
--- src/InitTweak/FixInit.cc	(revision 4e5e6cc70090e807822b56cfc8f3dc1ddaae698e)
+++ src/InitTweak/FixInit.cc	(revision aaeacf4b17e26df880b846210c264be0d6cc771b)
@@ -995,4 +995,9 @@
 			)
 
+
+			// std::set_difference requires that the inputs be sorted.
+			lvars.sort();
+			curVars.sort();
+
 			ObjectSet diff;
 			// S_L-S_G results in set of objects whose construction is skipped - it's an error if this set is non-empty