Index: deja-dup-21.4/deja-dup/AssistantOperation.vala
===================================================================
--- deja-dup-21.4.orig/deja-dup/AssistantOperation.vala
+++ deja-dup-21.4/deja-dup/AssistantOperation.vala
@@ -193,12 +193,12 @@ public abstract class AssistantOperation
       Gtk.TextIter start, line100;
       buffer.get_start_iter(out start);
       buffer.get_iter_at_line(out line100, buffer.get_line_count() - 100);
-      buffer.delete(start, line100);
+      buffer.delete(ref start, ref line100);
     }
     
     Gtk.TextIter iter;
     buffer.get_end_iter(out iter);
-    buffer.insert_text(iter, log_line, (int)log_line.length);
+    buffer.insert_text(ref iter, log_line, (int)log_line.length);
     if (adjustment_at_end)
       adjust.value = adjust.upper;
   }