[[ROS2]] is a bit tedious to debug, because it is inherently asynchronous and multi threaded.

A good way is to use VSCode for example like this:
https://gist.github.com/JADC362/a4425c2d05cdaadaaa71b697b674425f

As always the nav2 library is a good place for resources: [get backtrace explanation](https://navigation.ros.org/tutorials/docs/get_backtrace.html).
## Requirements
In order to run this we need to install gdbserver: `sudo apt install gdbserver`
## Launch Files
In the launch file, when adding a Node, add a `prefix="gdbserver localhost:3000"`:
```python
Node(
	package='nav3_controller',
	executable='controller_server',
	output='screen',
	respawn=use_respawn,
	respawn_delay=2.0,
	parameters=[configured_params],
	prefix='gdbserver localhost:3000',
	arguments=['--ros-args', '--log-level', log_level],
	remappings=remappings + [('offboard_cmd', 'offboard_velocity_cmd')]
)
```

This will create gdb as a server. Now we need to configure VSCode to attach to this debug session (as explained [here](https://answers.ros.org/question/267261/how-can-i-run-ros2-nodes-in-a-debugger-eg-gdb/)) add a new launch configuration like this:
```json
{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "C++ Debugger",
            "request": "launch",
            "type": "cppdbg",
            "miDebuggerServerAddress": "localhost:3000",
            "cwd": "/",
            "program": "[build-path-executable]"
        }
    ]
}
```