I can’t see messages using RCLCPP_DEBUG by terminal and rqt, but I can using other levels of verbosity( INFO, ERROR, FATAL…).Selecting debug in rqt to see those messages doesn’t work either.

I’m using rolling, working in C++ in a plugin of a controller and launching tb3_simulation_launch.py from nav2_bringup.

I also saw a post here where they recommended to set the environment variable:


but that didn’t work either. It must be something silly that I’m missing. Has this ever happened to you?

Thank you


1 Answer 1


You can try adding arguments=["--ros-args", "--log-level", "debug"], to the Node which you are interested in at the launch file.

Or in the case where you seem to be using the nav2_bringup straight, you can change it at https://github.com/ros-planning/navigation2/blob/ab9b1010d7a126c0c407cd09228d97068646ee4c/nav2_bringup/launch/navigation_launch.py#L134

You should also be able to give argument log_level:=debug when launching the launch file since that is being handled in the launch file. Downside is that then all nodes will have debug level and there will be lots of extras

Example of launch file addition

    controller_server = Node(
        output={"both": {"screen", "log", "own_log"}},
        arguments=["--ros-args", "--log-level", "debug"],
  • $\begingroup$ Thank you so much for your help. Adding log_level:=debug when launching the launch file worked perfectly. However, I couldn’t get it to work by modifying the launch file. $\endgroup$ Commented Feb 13 at 18:49
  • $\begingroup$ Great that you found this helpful. The modification of the launch file should also work. I have been using that for long time. Just have to be sure that the modified version is the one being ran. Added an example snippet from my code base. $\endgroup$ Commented Feb 14 at 10:18

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