Conflict with ROS Ignition Binaries

[bsb808]

I'm writing up this issue for posterity and to document the vulnerability.

Context

Working in dockwater galactic (see HonuRobotics/dockwater#25) and following the installation instructions: https://github.com/osrf/mbzirc, which includes cloning the galactic branch of the ros_ign repo and the running instructions https://github.com/osrf/mbzirc/wiki/Running-the-Demo.

Originally, I also included installation of ros-ign from binaries, e.g., apt install ros-galactic-ros-ign, in addition to installing from source.

Symptom: Runtime errors

The workspace builds without an error, but when running the example I get errors such as...

[ign gazebo-1] Error [Converter.cc:156] Unable to convert from SDF version 1.9 to 1.8
[ign gazebo-1] [Err] [SystemLoader.cc:66] Failed to load system plugin [ignition-gazebo-forcetorque-system] : couldn't find shared library.
[ign gazebo-1] [Err] [SystemLoader.cc:66] Failed to load system plugin [ignition-gazebo-rf-comms-system] : couldn't find shared library.

Solution

The ros_gz repo README indicates that for the combination of Galactic + Fortress support is "only from source" https://github.com/gazebosim/ros_gz

It appears that installing the https://github.com/gazebosim/ros_gz installs old versions of libignition* libraries that causes the error above.

It appears that apt install ros-galactic-ros-ign causes these conflicts and should be avoided.

[bsb808]

Closing my own issue.