diff --git a/src/plugins/alias/Alias.ml b/src/plugins/alias/Alias.ml
index b1143e01c4ae5aaa4b1747d47f53a12e632bb103..dbc33eef711b7171ffc8fedfd50307850c7ce565 100644
--- a/src/plugins/alias/Alias.ml
+++ b/src/plugins/alias/Alias.ml
@@ -29,6 +29,6 @@ let main () =
       Analysis.compute ();
       Options.feedback "Analysis complete";
     end
-    
+
 let () =
   Db.Main.extend main
diff --git a/src/plugins/alias/abstract_state.ml b/src/plugins/alias/abstract_state.ml
index 4cd5c110cab3ac53df69ee71580e66da9e732dcd..01b59fcfa599b6d75e8a181488ceafcfa49f59f6 100644
--- a/src/plugins/alias/abstract_state.ml
+++ b/src/plugins/alias/abstract_state.ml
@@ -297,11 +297,10 @@ let remove_lval (x:t)  (lv:lval) :t =
 let find_vertex_name_ref = Extlib.mk_fun "find_vertex_name"
 
 
-let lset_to_string s =
-  let buffer = Buffer.create 16 in
-  let fmt = Format.formatter_of_buffer buffer in
-  Format.fprintf fmt "%a" LSet.pretty s ;
-  Buffer.contents buffer
+let lset_to_string (s: LSet.t) : string =
+  let fmt = Format.str_formatter in
+  Format.fprintf fmt "\"%a\"" LSet.pretty s;
+  Format.flush_str_formatter ()
 
 module Dot = Graphviz.Dot(struct
     include G
@@ -311,7 +310,9 @@ module Dot = Graphviz.Dot(struct
     let vertex_attributes _ = [`Shape `Box]
     let vertex_name (v:V.t) =
       let lset = !find_vertex_name_ref v in
-      lset_to_string lset
+      let v_name = lset_to_string lset in
+      Format.printf "Vertex %d set %s@." v v_name;
+      v_name
     let default_vertex_attributes _ = []
     let graph_attributes _ = []
   end)
diff --git a/src/plugins/alias/analysis.ml b/src/plugins/alias/analysis.ml
index bbadf5c6d4ad7c01ef3581495982eea4357b115f..5b4e214c27b6ba54fcf7696eb1757ff2361f2007 100644
--- a/src/plugins/alias/analysis.ml
+++ b/src/plugins/alias/analysis.ml
@@ -103,7 +103,7 @@ let do_assignment (a:Abstract_state.t option) (lv:lval) (exp:exp) : Abstract_sta
     begin
       match e1.enode with
         Lval lv1 -> Some (Abstract_state.assignment_ptr_x_y a lv1 lv2)
-      |  _ -> (Options.feedback "Skipping assignment @[%a@] = @[%a@] (BUG do_assignment 2)" Lval.pretty lv Exp.pretty exp; Some a) 
+      |  _ -> (Options.feedback "Skipping assignment @[%a@] = @[%a@] (BUG do_assignment 2)" Lval.pretty lv Exp.pretty exp; Some a)
     end
   (* cases *x = cst *)
   | (Some a, (Mem e1, NoOffset), BNone) ->