`ros2 topic echo` missing required positional argument `info`

torrhen commented 2 years ago

Bug report

Required Info:

Operating System: Ubuntu 20.04.4 LTS
Installation type: Source
Version or commit hash: f46fa80c5bffe95b45fbba2e5cda724f3e4e8cce
DDS implementation: Cyclone DDS
Client library (if applicable): rclpy

Steps to reproduce issue

Caused when attempting to print the messages sent/received over a topic. The example below highlights this with a turtlesim example, but the same error is reproducible for talker and listener nodes over the /chatter topic.

ros2 topic echo /turtle1/cmd_vel

Expected behavior

linear:
  x: 2.0
  y: 0.0
  z: 0.0
angular:
  x: 0.0
  y: 0.0
  z: 0.0
---

Actual behavior

Traceback (most recent call last):
  File "XXXX/install/ros2cli/bin/ros2", line 11, in <module>
    load_entry_point('ros2cli', 'console_scripts', 'ros2')()
  File "XXXX/build/ros2cli/ros2cli/cli.py", line 89, in main
    rc = extension.main(parser=parser, args=args)
  File "XXXX/build/ros2topic/ros2topic/command/topic.py", line 41, in main
    return extension.main(args=args)
  File "XXXX/build/ros2topic/ros2topic/verb/echo.py", line 243, in main
    self.subscribe_and_spin(
  File "XXXX/build/ros2topic/ros2topic/verb/echo.py", line 286, in subscribe_and_spin
    rclpy.spin(node)
  File "XXXX/install/rclpy/lib/python3.8/site-packages/rclpy/__init__.py", line 222, in spin
    executor.spin_once()
  File "XXXX/install/rclpy/lib/python3.8/site-packages/rclpy/executors.py", line 712, in spin_once
    raise handler.exception()
  File "XXXX/install/rclpy/lib/python3.8/site-packages/rclpy/task.py", line 239, in __call__
    self._handler.send(None)
  File "XXXX/install/rclpy/lib/python3.8/site-packages/rclpy/executors.py", line 418, in handler
    await call_coroutine(entity, arg)
  File "XXXX/install/rclpy/lib/python3.8/site-packages/rclpy/executors.py", line 343, in _execute_subscription
    await await_or_execute(sub.callback, msg)
  File "XXXX/rclpy/lib/python3.8/site-packages/rclpy/executors.py", line 107, in await_or_execute
    return callback(*args)
TypeError: _subscriber_callback() missing 1 required positional argument: 'info'

Additional information

The same error is thrown when including the information of a message over the topic, e.g. ros2 topic echo /turtle1/cmd_vel --include-message-info --csv

A temporary fix can be found by providing a default argument to the _subscriber_callback method below on line 288 within ros2topic/verb/echo.py

    def _subscriber_callback(self, msg, info='Default'):
        submsg = msg
        if self.field is not None:
            for field in self.field:
                try:
                    submsg = getattr(submsg, field)
                except AttributeError as ex:
                    raise RuntimeError(f"Invalid field '{'.'.join(self.field)}': {ex}")

This gives the expected behaviour for the ordinary ros2 topic echo <topic-name> example above as well for ros2 topic echo --include-message-info <topic-name> with or without --raw (which prints the 'Default' string before each message in this case).

However, this does not help with --include-message-info --csv as it raises an entirely new error.

fujitatomoya commented 2 years ago

I cannot reproduce this issue on Ubuntu 20.04 or 22.04 with https://github.com/ros2/ros2/commit/28a83a843324918293ccd0d106117cf2fa4e33a6 (cyclonedds and fastdds just works okay.)

torrhen commented 2 years ago

New install and build resolved the issue in the end. Thanks for checking regardless.

ros2 / ros2cli