Skip to main content
Version: 1.5.0

Workspace build of ROS2 packages

This guide shows how to set up a workspace in ROS2. If you encounter any issues during the process, see the end of this page for Troubleshooting of common issues.

Installation steps​

1. Install the Robot Operating System (Jazzy)​

Follow the ROS2 Installation guide.

2. Install the MRS UAV Core with necessary dependencies​

Follow the ROS2 MRS UAV Core Installation guide.

3. Get aliases that make common ROS2 commands usable​

By default, calling colcon build anywhere creates a workspace there (even in a subdirectory of an workspace). To prevent that, the aliased colcon build crawls back in the directory tree to check if we are in a workspace and if not, will NOT create a workspace automatically. With the aliases, a workspace can be created only by colcon init similarly to catkin_tools in ROS1.

cd ~/git
git clone git@github.com:ctu-mrs/mrs_uav_development.git
cd mrs_uav_development
git checkout ros2

Add to ~/.bashrc (~/.zshrc):

source $HOME/git/mrs_uav_development/shell_additions/shell_additions.sh

4. Clone the ROS2 Examples package​

cd ~/git
git clone git@github.com:ctu-mrs/ros2_examples.git

5. Prepare the workspace​

mkdir -p ~/ws_examples/src
ln -s $HOME/git/ros2_examples $HOME/ws_examples/src/

Now we need to set the workspace compilation flags using mixin.

First, install mixin

sudo apt install python3-colcon-mixin

then add default mixin

colcon mixin add default https://raw.githubusercontent.com/colcon/colcon-mixin-repository/master/index.yaml
colcon mixin update default

finally add MRS mixin

colcon mixin add mrs https://raw.githubusercontent.com/ctu-mrs/mrs_uav_development/refs/heads/ros2/mixin/index.yaml
colcon mixin mrs default

Add the following config to ~/ws_examples/colcon_defaults.yaml to set the number of build threads to 8 and build with the "rel-with-deb-info" mixin profile:

build:
  parallel-workers: 8
  mixin:
    - rel-with-deb-info

For more information regarding setting workspace flags using mixins see ROS2 Workspace Profiles

6. Build the workspace​

cd ~/ws_examples/
colcon init
colcon build

Add to ~/.bashrc (~/.zshrc):

export ROS_WORKSPACE="$HOME/ws_examples"

Troubleshooting

Optimization flags​

  • Issue: Estimation manager is outputting errors with time since last msg too long
  • Reason: Workspace is built without optimization flags.
  • Solution: See step 5. and make sure the workspace is built with rel_with_deb_info

Tmux config​

  • Issue: After running the tmux session, the terminal looks weird and tmux bindings don't work
  • Reason: tmux config is missing in /etc/ctu-mrs/tmux.conf
  • Solution: sudo apt install mrs-uav-shell-additions

MRS UAV testing not building​

  • Issue: The package mrs_uav_testing is not building
  • Reason: It hasn't been converted to ROS2 yet.
  • Solution: touch ~/ws_mrs_uav_core/src/mrs_uav_core/ros_packages/mrs_uav_testing/COLCON_IGNORE

Colcon build not working as expected​

  • Issue: Calling colcon build does not create a workspace and start building it.
  • Reason: We have an alias for colcon, to make its usage less awkward. See step 3 for details.
  • Solution: First call colcon init in the root of the workspace, then colcon build.