Rosanswers logo

Good day all,

My setup:

  • Ubuntu 22.04 Desktop

  • Humble Hawksbill

  • Raspberry Pi 4

I have just installed Humble and I am working my way through the tutorials.

I have reached this point: https://docs.ros.org/en/humble/Tutorials/Beginner-Client-Libraries/Colcon-Tutorial.html

After grabbing the ROS2 examples: git clone https://github.com/ros2/examples src/examples -b humble and then running colcon build --symlink-install , the build hangs indefinitely with the following output:

[3.931s] WARNING:colcon.colcon_core.package_selection:Some selected packages are already built in one or more underlay workspaces:
    'examples_rclcpp_multithreaded_executor' is in: /opt/ros/humble
    'examples_rclpy_minimal_client' is in: /opt/ros/humble
    'examples_rclcpp_minimal_composition' is in: /opt/ros/humble
    'examples_rclcpp_minimal_timer' is in: /opt/ros/humble
    'examples_rclcpp_minimal_subscriber' is in: /opt/ros/humble
    'examples_rclpy_minimal_publisher' is in: /opt/ros/humble
    'examples_rclcpp_minimal_service' is in: /opt/ros/humble
    'examples_rclpy_minimal_action_server' is in: /opt/ros/humble
    'examples_rclpy_executors' is in: /opt/ros/humble
    'examples_rclpy_minimal_subscriber' is in: /opt/ros/humble
    'examples_rclcpp_minimal_action_server' is in: /opt/ros/humble
    'examples_rclcpp_minimal_publisher' is in: /opt/ros/humble
    'examples_rclpy_minimal_service' is in: /opt/ros/humble
    'examples_rclcpp_minimal_client' is in: /opt/ros/humble
    'examples_rclpy_minimal_action_client' is in: /opt/ros/humble
    'examples_rclcpp_minimal_action_client' is in: /opt/ros/humble
If a package in a merged underlay workspace is overridden and it installs headers, then all packages in the overlay must sort their include directories by workspace order. Failure to do so may result in build failures or undefined behavior at run time.
If the overridden package is used by another package in any underlay, then the overriding package in the overlay must be API and ABI compatible or undefined behavior at run time may occur.

If you understand the risks and want to override a package anyways, add the following to the command line:
    --allow-overriding examples_rclcpp_minimal_action_client examples_rclcpp_minimal_action_server examples_rclcpp_minimal_client examples_rclcpp_minimal_composition examples_rclcpp_minimal_publisher examples_rclcpp_minimal_service examples_rclcpp_minimal_subscriber examples_rclcpp_minimal_timer examples_rclcpp_multithreaded_executor examples_rclpy_executors examples_rclpy_minimal_action_client examples_rclpy_minimal_action_server examples_rclpy_minimal_client examples_rclpy_minimal_publisher examples_rclpy_minimal_service examples_rclpy_minimal_subscriber

This may be promoted to an error in a future release of colcon-override-check.
Starting >>> examples_rclcpp_async_client
Starting >>> examples_rclcpp_cbg_executor
Starting >>> examples_rclcpp_minimal_action_client
Starting >>> examples_rclcpp_minimal_action_server                          
[Processing: examples_rclcpp_async_client, examples_rclcpp_cbg_executor, examples_rclcpp_minimal_action_client, examples_rclcpp_minimal_action_server]                                             
[Processing: examples_rclcpp_async_client, examples_rclcpp_cbg_executor, examples_rclcpp_minimal_action_client, examples_rclcpp_minimal_action_server]                                             
[1min 9.2s] [0/22 complete] [4 ongoing] [examples_rclcpp_async_client:build 50% - 1min 7.7s] [examples_rclcpp_cbg_executor:build 40% - 1min 7.6s] ...

The timer continues to tick up to about 20 minutes without making progress. I killed the process at this point.

Anyone able to assist please? The error itself is quite clear. But why this should come during working through the tutorials, makes me wonder if the tutorials should be amended. Or, could be there is an issue with my system. Thanks in advance.


Originally posted by BryanGD on ROS Answers with karma: 3 on 2022-07-22

Post score: 0

Original comments

Comment by BryanGD on 2022-07-25:
Thanks @gvdhoorn for the edit.


1 Answer 1


Rosanswers logo

To start off, the warning isn't related to the build not progressing. It's just warning you that the packages you are building were included in the ROS desktop installation (and can have potential problems, etc.), which is not a concern here.

In regards to the build taking forever, unfortunately the issue isn't apparent from the log you posted. You could try building verbosely (and one package at a time so we don't see the terminal getting spammed by four parallel build processes), and have a closer look at what exactly is taking long:

colcon build --symlink-install --executor sequential --event-handlers console_direct+

Originally posted by ijnek with karma: 460 on 2022-07-23

This answer was ACCEPTED on the original site

Post score: 1

Original comments

Comment by BryanGD on 2022-07-25:
Thanks @ijnek. Running your suggestion now and the build is slowly working through the packages ( [12 minutes] [11/22 complete] ). I guess previously it wasn't showing the progress and I was too impatient, expecting it to be a lot quicker than ~20 minutes.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.