https://sourceforge.net/p/etherape/etherape/ci/f7a80a33b38edd97368be1cd8d13aaea321bf4e7/

--- etherape-0.9.20/src/diagram.c
+++ etherape-0.9.20/src/diagram.c
@@ -170,7 +170,7 @@
 static void diagram_update_nodes(GooCanvas *canvas); /* updates ALL nodes */
 static void diagram_update_links(GooCanvas *canvas); /* updates ALL links */
 static void diagram_update_background_image(GooCanvas *canvas); /* updates background image */
-static void diagram_reposition(); /* reposition nodes */
+static void diagram_reposition(GooCanvas *canvas); /* reposition nodes */
 
 static void check_new_protocol(GtkWidget *prot_table, const protostack_t *pstk);
 static gint check_new_node(node_t *node, GooCanvas *canvas);