Index: src/solver.d
==================================================================
--- src/solver.d
+++ src/solver.d
@@ -347,11 +347,11 @@
 			replan();
 
 		// Follow the predicted plan.
 		if( plan.empty )
 			return 'A';
-writeln(plan, " ", plan_state);
+stderr.writeln(plan, " ", plan_state);
 		char c = plan[0];
 		plan = plan[1..$];
 		current_game.command(c);
 		return c;
 	}
@@ -390,11 +390,11 @@
 		}
 	}
 
 	void replan()
 	{
-writeln("replan!");
+stderr.writeln("replan!");
 		// Try to replace every step of the plan by another move.
 		Game g = current_game.clone();
 		Tuple!(long, SubSolver, string, int) cand =
 			tuple(sub_solver.g.score, sub_solver, plan, Tentative_Stuck);
 		for(int i=0; i<plan.length; ++i) {