fix dot graph construction

src/kyupy/circuit.py

@@ -652,11 +652,11 @@ class Circuit:
                 region.append(n)
             yield stem, region
 
-    def dot(self, format='svg', graph_attr={}, line_labels={}):
+    def dot(self, tlib: 'TechLib', format='svg', graph_attr={}, line_labels={}):
         from graphviz import Digraph
         dot = Digraph(format=format, graph_attr={'rankdir': 'LR', 'splines': 'true', 'size': '10', 'ranksep': '0.1'} | graph_attr)
 
-        s_dict = dict((n, i) for i, n in enumerate(self.s_nodes))
+        s_dict = dict((n, i) for i, n in enumerate(self.s_nodes(tlib)))
         node_level = np.zeros(len(self.nodes), dtype=np.uint32)
         level_nodes = defaultdict(list)
         for n, lv in self.topological_order_with_level():
@@ -679,7 +679,7 @@ class Circuit:
             reader = f'{l.reader.index}:i{l.reader_pin}' if len(l.reader.ins)>1 else f'{l.reader.index}'
             label = str(line_labels.get(l, l.index))
             if node_level[l.driver] == node_level[l.reader]:
-                s.node(f'_{l.index}_')
+                dot.node(f'_{l.index}_')
                 dot.edge(driver, f'_{l.index}_', style='dotted', label=label)
                 dot.edge(f'_{l.index}_', reader, style='dotted', label=label)
             elif node_level[l.driver] > node_level[l.reader]: