Prevent installation of ROS packages when using rosdep

[xfiderek]

Hi!
Is it possible to install only non-ROS related dependencies with rosdep? For example to skip installation of APT packages coming from http://packages.ros.org/ros2/ubuntu repository? Or ideally to throw an error when ROS packages are to be installed?
The use case that I have is that I am building ROS from source and I want to install non-ROS dependencies such as python3-sqlalchemy, but I want to throw an error when packages such as ros-humble-nav2-msgs are to be installed via apt.

The approach that I came up with so far is something like:

set -e
rosdep install --from-paths src -s | grep 'ros-humble' && exit 1
rosdep install --from-paths src

I wanted to check if there is a cleaner way to achieve it.

[nuclearsandwich]

If you know which ROS packages you are providing, you can skip installing them with the with --skip-keys.

If your entire ROS from source configuration is in your src directory, you can use --ignore-src which will ignore packages that are found in-workspace.

What you might want to consider instead is using https://github.com/ros-infrastructure/rosinstall_generator to generate the source workspace with all ROS dependencies and then you can use that workspace together with rosdep install --from-paths src --ignore-src to get only system-level dependencies.