Exception while calling service of node '<my_node>' : None
When running navigation2 and then calling ros2 param list, I get following errors:
- Exception while calling service of node '/btnavigatorrclcpp_node': None
- Exception while calling service of node '/controller_server': None
- Exception while calling service of node '/globalcostmapclient': None
- Exception while calling service of node '/lifecyclemanagernavigation': None
- Exception while calling service of node '/localcostmapclient': None
- Exception while calling service of node '/waypointfollowerrclcpp_node': None
How to reproduce
- Copy the foxy navigation 2 launch file into own workspace
- Run with the default param file
Environment
- foxy (0.9.2-1focal.20211119.123452)
- Ubuntu 20.04
Additional Information
Switching to Galactic yields following (related) error:
Exception while calling service of node '/bt_navigatornavigate_through_poses_rclcpp_node': None
Traceback (most recent call last):
File "/opt/ros/galactic/bin/ros2", line 11, in <module>
load_entry_point('ros2cli==0.13.1', 'console_scripts', 'ros2')()
File "/opt/ros/galactic/lib/python3.8/site-packages/ros2cli/cli.py", line 67, in main
rc = extension.main(parser=parser, args=args)
File "/opt/ros/galactic/lib/python3.8/site-packages/ros2param/command/param.py", line 39, in main
return extension.main(args=args)
File "/opt/ros/galactic/lib/python3.8/site-packages/ros2param/verb/list.py", line 116, in main
sorted_names = sorted(response.result.names)
AttributeError: 'NoneType' object has no attribute 'result'
Asked by Fellfalla on 2022-02-01 03:53:59 UTC
Answers
Hi,
the exceptions seems to be thrown here:
https://github.com/ros2/ros2cli/blob/6cbe07025506233120703bc88e6a2123615e2e97/ros2param/ros2param/verb/list.py#L113
It might be good to open an issue on ros2/ros2cli for that, because the service future returns None although there seems to be no exception set (None).
The reason for this behavior might be that the list_parameters service of the lifecycle nodes you are using is not running or not ready. In which state are the nodes, do they reach configured state?
In general I made the experience that the Nav2 stack is much more mature in ROS2 Galactic.
Asked by Karl on 2022-02-02 04:14:22 UTC
Comments
Subscribing to /controller_server/transition_event, It seems like the node is passing following states:
1. unconfigured -> configuring
2. configuring -> inactive
3. inactive -> activating
I wasn't able to find any lifecycle_state topic
Asked by Fellfalla on 2022-02-02 05:38:57 UTC
Comments