pgraph: Disable non-working `__traverse__()` on NodePath

panda/src/pgraph/nodePath.h

@@ -947,7 +947,7 @@ PUBLISHED:
   PY_EXTENSION(NodePath find_net_python_tag(PyObject *keys) const);
   PY_MAKE_PROPERTY(python_tags, get_python_tags);
 
-  PY_EXTENSION(int __traverse__(visitproc visit, void *arg));
+  //PY_EXTENSION(int __traverse__(visitproc visit, void *arg));
 
   INLINE void list_tags() const;
 

panda/src/pgraph/nodePath_ext.I

@@ -135,10 +135,10 @@ has_net_python_tag(PyObject *key) const {
 /**
  * Called by Python to implement cycle detection.
  */
-INLINE int Extension<NodePath>::
+/*INLINE int Extension<NodePath>::
 __traverse__(visitproc visit, void *arg) {
   if (_this->is_empty()) {
     return 0;
   }
   return invoke_extension(_this->node()).__traverse__(visit, arg);
-}
+}*/

panda/src/pgraph/nodePath_ext.h

@@ -48,7 +48,7 @@ public:
   NodePath find_net_python_tag(PyObject *key) const;
 
   // This is defined to implement cycle detection in Python tags.
-  INLINE int __traverse__(visitproc visit, void *arg);
+  //INLINE int __traverse__(visitproc visit, void *arg);
 
   void set_shader_input(CPT_InternalName id, PyObject *value, int priority=0);
   void set_shader_inputs(PyObject *args, PyObject *kwargs);