Action client crashes "no attribute 'sequence'"

[sloretz]

Bug report

Required Info:

• Operating System:
  • Ubuntu 18.04
• Installation type:
  • source
• Version or commit hash:
  • master
• DDS implementation:
  • Fast-RTPS
• Client library (if applicable):
  • rclpy

Steps to reproduce issue

In one terminal start the server

ros2 run examples_rclpy_minimal_action_server server

In another terminal start the client

ros2 run examples_rclpy_minimal_action_client client

Expected behavior

Client prints feedback as it receives it

Actual behavior

Client crashes

$ ros2 run examples_rclpy_minimal_action_client client
[INFO] [minimal_action_client]: Waiting for action server...
[INFO] [minimal_action_client]: Sending goal request...
[INFO] [minimal_action_client]: Goal accepted :)
Traceback (most recent call last):
  File "/home/sloretz/ws/ros2/install/examples_rclpy_minimal_action_client/lib/examples_rclpy_minimal_action_client/client", line 11, in <module>
    load_entry_point('examples-rclpy-minimal-action-client', 'console_scripts', 'client')()
  File "/home/sloretz/ws/ros2/build/examples_rclpy_minimal_action_client/examples_rclpy_minimal_action_client/client.py", line 76, in main
    rclpy.spin(action_client)
  File "/home/sloretz/ws/ros2/install/rclpy/lib/python3.6/site-packages/rclpy/__init__.py", line 178, in spin
    executor.spin_once()
  File "/home/sloretz/ws/ros2/install/rclpy/lib/python3.6/site-packages/rclpy/executors.py", line 605, in spin_once
    raise handler.exception()
  File "/home/sloretz/ws/ros2/install/rclpy/lib/python3.6/site-packages/rclpy/task.py", line 206, in __call__
    self._handler.send(None)
  File "/home/sloretz/ws/ros2/install/rclpy/lib/python3.6/site-packages/rclpy/executors.py", line 351, in handler
    await call_coroutine(entity, arg)
  File "/home/sloretz/ws/ros2/install/rclpy/lib/python3.6/site-packages/rclpy/executors.py", line 317, in _execute_waitable
    await waitable.execute(data)
  File "/home/sloretz/ws/ros2/install/rclpy/lib/python3.6/site-packages/rclpy/action/client.py", line 306, in execute
    await await_or_execute(self._feedback_callbacks[goal_uuid], feedback_msg)
  File "/home/sloretz/ws/ros2/install/rclpy/lib/python3.6/site-packages/rclpy/executors.py", line 119, in await_or_execute
    return callback(*args)
  File "/home/sloretz/ws/ros2/build/examples_rclpy_minimal_action_client/examples_rclpy_minimal_action_client/client.py", line 41, in feedback_callback
    self.get_logger().info('Received feedback: {0}'.format(feedback.sequence))
AttributeError: 'Fibonacci_FeedbackMessage' object has no attribute 'sequence'

[jacobperron]

This affects all of the action client examples. I'm guessing it is a regression following ros2/rosidl_python#35, but I'll look into it.

[dirk-thomas]

I'm guessing it is a regression following ros2/rosidl_python#35, but I'll look into it.

The reference PR only changes the type of attributes but doesn't add/remove any attributes.