Fail package if conflicting source configuration is found

[claraberendsen]

Description

If a previous manual installation of the ROS repositories is found the package gets installed and breaks the apt installation process (See sloretz/ros_oci_images#26)

To address this it would be nice to be able to fail on package installation on conflict as to avoid breaking apt in the end user computer.

[danzimmerman]

Yes, this is now an issue with the official install instructions for Kilted. I expect this could affect a lot of people who try to install side-by-side with Jazzy like I was trying to do.

Originally I restored apt functionality with:

sudo rm /etc/apt/sources.list.d/ros2.sources

Then

sudo apt remove ros2-apt-source

to revert. But I think the existing signing key is due to expire soon? https://discourse.ros.org/t/ros-signing-key-expiracy/43826

In the end I manually deleted /etc/apt/sources.list.d/ros2.list instead and reinstalled the ros2-apt-source package from the Kilted instructions.

Then ros2.sources is softlinked to the ros-apt-source package install location:

(kilted) dan@<computer name>:/etc/apt/sources.list.d$ls -al
total 20
drwxr-xr-x 2 root root 4096 May 24 12:41 .
drwxr-xr-x 9 root root 4096 Dec  7 00:49 ..
-rw-r--r-- 1 root root  143 Apr 28 23:04 gazebo-stable.list
lrwxrwxrwx 1 root root   38 Mar 14  2024 ros2.sources -> /usr/share/ros-apt-source/ros2.sources
-rw-r--r-- 1 root root  386 Dec  7 00:49 ubuntu.sources
-rw-r--r-- 1 root root 2552 Aug 27  2024 ubuntu.sources.curtin.orig

Removing /etc/apt/sources.list.d/ros2.list from the Jazzy install instructions allows me to install and update both Jazzy and Kilted packages. After that I guess there's no reason to keep /usr/share/keyrings/ros-archive-keyring.gpg around, so I deleted that as well.

[claraberendsen]

Thanks @danzimmerman for the detail update. I missed releasing the migration guide in time for the Kilted release, but here it is https://discourse.ros.org/t/ros-signing-key-migration-guide/43937. The steps are similar to the ones you have done.