diff --git a/include/ui.h b/include/ui.h
index 6c2b887..4770240 100644
--- a/include/ui.h
+++ b/include/ui.h
@@ -124,6 +124,5 @@ void ui_toggle_sidebar              ();
 
 void print_test_in_tree_dot_c(void);
 
-//GtkWidget *create_tree_label(void);
-GtkWidget *create_a_button_to_click_on(GemGraphClientWindow *window);
-//GtkWidget *create_a_button_in_the_tab(GemGraphClientWindow *window);
+// GtkWidget *create_a_button_to_click_on(GemGraphClientWindow *window);
+
diff --git a/manifest.scm b/manifest.scm
index 783fa88..c19b4d9 100644
--- a/manifest.scm
+++ b/manifest.scm
@@ -5,6 +5,24 @@
 
 (specifications->manifest
   (list
+      "bash"
+      "coreutils"
+      "gcc-toolchain"
+      "pkg-config"
+      "valgrind"
+      "findutils"
+      "gdb"
       "make"
+      "gtk"
+      "libxml2"
+      "glew"
+      "glfw"
+      "libepoxy"
+      "pango@1.90.0"
+      "xorgproto"
+      "glib"
+      "mesa-headers"
+      "mesa"
+      "libadwaita"
    )
-)
\ No newline at end of file
+)
diff --git a/src/ui/tree.c b/src/ui/tree.c
index bef5ac8..8a9b7b9 100644
--- a/src/ui/tree.c
+++ b/src/ui/tree.c
@@ -255,7 +255,7 @@ struct _TreeItem
   TreeItem       *children;
 };
 
-/* tree data */
+//  tree data
 /* static TreeItem E[] = {NULL}, F[] = {NULL}, G[] = {NULL}, H[] = {NULL}; */
 /* static TreeItem I[] = {NULL}, K[] = {NULL}, N[] = {NULL}, M[] = {NULL}; */
 /* static TreeItem L[] = {{"M", M}, {"N", N}, {NULL }}, J[] = {{"L", L}, {NULL}}; */
@@ -267,17 +267,20 @@ struct _TreeItem
 
 
 /* static GListStore *create_node_recursive (GListModel *model,  //  GListStore* g_list_store_new (GType item_type) */
-/*                                             TreeItem *current_item, */
-/*                                             GtkTreeIter *iter_parent, */
-/*                                             int depth) */
+/*                                    TreeItem *current_item, */
+/*                                    GtkTreeIter *iter_parent, */
+/*                                    int depth) */
 /* { */
+/*   if (model == NULL) */
+/*     printf("tree.c   >   print test()   create_node_recursive\n"); */
+
 /*   GtkTreeIter iter; */
 
 /*   if (model == NULL) */
 /*       model = gtk_tree_store_new (NUM_COLUMNS, G_TYPE_STRING); */
 
 /*   while (current_item->label) { */
-/*     if (0) printf("[%d] Current label : %s\n", depth, current_item->label); */
+/*     if (1) printf("[%d] Current label : %s\n", depth, current_item->label); */
 /*     gtk_tree_store_append (model, &iter, iter_parent); */
 /*     gtk_tree_store_set (model, &iter, STRING_COLUMN, current_item->label, -1); */
 
@@ -297,29 +300,33 @@ struct _TreeItem
 
 
 
-static void
-print_hello (GtkWidget *widget,
-             gpointer   data)
-{
-    static int nb;
-    nb++;
-    printf("Button clicked  (n = %d)\n", nb);
-}
+/* static void */
+/* print_hello (GtkWidget *widget, */
+/*              gpointer   data) */
+/* { */
+/*     static int nb; */
+/*     nb++; */
+/*     printf("Button clicked  (n = %d)\n", nb); */
+/* } */
 
-GtkWidget *create_a_button_to_click_on(GemGraphClientWindow *my_window)
-{
-    GtkWidget *button;
-    const char *text = "Hello !  I'm the new button.   Click me !";
+/* GtkWidget *create_a_button_to_click_on(GemGraphClientWindow *my_window) */
+/* { */
+/*     GtkWidget *button; */
+/*     const char *text = "Hello !  I'm the new button.   Click me !"; */
 
-    button = gtk_button_new_with_label(text);
-    gtk_box_append(GTK_BOX(my_window->runlib_objects), button);
-    gtk_widget_show(button);
+/*     button = gtk_button_new_with_label(text); */
+/*     gtk_box_append(GTK_BOX(my_window->runlib_objects), button); */
+/*     gtk_widget_show(button); */
 
-    g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
+/*     g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL); */
 
+/*     printf("tree.c   >   print test()   \ */
+/* ------------------------------------\nClick the 'new button' in the GtkBox.\n"); */
+
+/*     return button; */
+/* } */
+
+void print_test_in_tree_dot_c() {
     printf("tree.c   >   print test()   \
 ------------------------------------\nClick the 'new button' in the GtkBox.\n");
-
-    return button;
 }
-
diff --git a/src/ui/window.c b/src/ui/window.c
index d2c09f0..6f4f55a 100644
--- a/src/ui/window.c
+++ b/src/ui/window.c
@@ -124,7 +124,7 @@ static void gem_graph_client_window_init(GemGraphClientWindow *self)
 
 /* -------------------------------------------------------------------------- */
 
-GtkWidget *create_a_button_to_click_on(void);
+GtkWidget *create_a_button_to_click_on(GemGraphClientWindow *my_window);
 
 void ui_set_stack(const char *mode)
 {
@@ -142,6 +142,8 @@ void ui_set_stack(const char *mode)
         case 'r':
             gtk_menu_button_set_icon_name(window->main_button_mode, "system-run-symbolic");
             create_a_button_to_click_on(window);
+         //   let_s_scroll_it_guys();
+            print_test_in_tree_dot_c();
 
             break;
         case 'p':
@@ -252,3 +254,28 @@ void ui_toggle_sidebar(void)
     else               gtk_paned_set_position(window->main_paned, 400);
 }
 
+
+
+static void
+print_hello (GtkWidget *widget,
+             gpointer   data)
+{
+    static int nb;
+    nb++;
+    printf("Button clicked  (n = %d)\n", nb);
+}
+
+GtkWidget *create_a_button_to_click_on(GemGraphClientWindow *my_window)
+{
+    GtkWidget *button;
+    const char *text = "Hello !  I'm the new button.   Click me !";
+
+    button = gtk_button_new_with_label(text);
+    gtk_box_append(GTK_BOX(my_window->runlib_objects), button);
+    gtk_widget_show(button);
+
+    g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
+
+    return button;
+}
+