ros2 node list doesn not show node - Raspberry Pico

edit

The solution was related more on the compiler for the Raspberry which for microros requires the 9.3.1 and not the 6.3.1 which is the one downloaded on ubuntu 18. The solution of the issue is here: Github. It still remain // in the node list:

ros2 node list
//
/pico_node

But now it works. The only drawbacks that due to the fact of the node "//", rqt crashes when I am trying to see the node graph:

[ERROR] [rmw_fastrtps_shared_cpp]: Unable to find GUID for node: /
PluginManager._load_plugin() could not load plugin "rqt_graph/RosGraph":
Traceback (most recent call last):
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/plugin_handler.py", line 102, in load
    self._load()
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/plugin_handler_direct.py", line 55, in _load
    self._plugin = self._plugin_provider.load(self._instance_id.plugin_id, self._context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/rqt_gui_py/ros_py_plugin_provider.py", line 64, in load
    return super(RosPyPluginProvider, self).load(plugin_id, ros_plugin_context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/rqt_gui/ros_plugin_provider.py", line 107, in load
    return class_ref(plugin_context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/rqt_graph/ros_graph.py", line 193, in __init__
    self._update_rosgraph()
  File "/opt/ros/dashing/lib/python3.6/site-packages/rqt_graph/ros_graph.py", line 285, in _update_rosgraph
    self._graph.update()
  File "/opt/ros/dashing/lib/python3.6/site-packages/rqt_graph/rosgraph2_impl.py", line 495, in update
    updated = self._graph_refresh()
  File "/opt/ros/dashing/lib/python3.6/site-packages/rqt_graph/rosgraph2_impl.py", line 307, in _graph_refresh
    self._node.get_publisher_names_and_types_by_node(name, namespace):
  File "/opt/ros/dashing/lib/python3.6/site-packages/rclpy/node.py", line 1429, in get_publisher_names_and_types_by_node
    capsule, no_demangle, node_name, node_namespace)
RuntimeError: Failed to get_publisher_names_and_types: Unable to find GUID for node , at /tmp/binarydeb/ros-dashing-rmw-fastrtps-shared-cpp-0.7.8/src/rmw_node_info_and_types.cpp:87

[ERROR] [rmw_fastrtps_shared_cpp]: Unable to find GUID for node: /
PluginManager._load_plugin() could not load plugin "rqt_graph/RosGraph":
Traceback (most recent call last):
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/plugin_handler.py", line 102, in load
    self._load()
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/plugin_handler_direct.py", line 55, in _load
    self._plugin = self._plugin_provider.load(self._instance_id.plugin_id, self._context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/rqt_gui_py/ros_py_plugin_provider.py", line 64, in load
    return super(RosPyPluginProvider, self).load(plugin_id, ros_plugin_context)
  File "/opt/ros/dashing/lib/python3.6/site-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)
  File "/opt ...