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gazebosim / ros_gz

Integration between ROS (1 and 2) and Gazebo simulation
https://gazebosim.org
Apache License 2.0
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executable name from gz_sim.launch.py #547

Closed christophfroehlich closed 4 months ago

christophfroehlich commented 4 months ago

How is this supposed to work with ruby?

https://github.com/gazebosim/ros_gz/blob/78dc4823121f085594e6028a93f1e571eb04f58b/ros_gz_sim/launch/gz_sim.launch.py.in#L45-L51

The executable name just remains ruby $(which gz) sim, see for example the CI in gz_ros2_control. Is there something missing to be installed?

mjcarroll commented 4 months ago

I believe that it's just using simple shell expansion $() which gets evaluated before running ruby.

christophfroehlich commented 4 months ago

Ok, so might it be that this an effect of launch.actions.ExecuteProcess, which creates a logger with a name being this command, but the command gets evaluated correctly when actually launching the executable? At least, it does not make the log files very readable (neither in our CI, nor in log files posted e.g. on stack exchange)

christophfroehlich commented 4 months ago

May I ask why there is a need for ruby at all?

azeey commented 4 months ago

500 and related PRs should help with this since Gazebo will be ran as a ROS node.

May I ask why there is a need for ruby at all?

Ruby is needed because the gz is written in Ruby (https://github.com/gazebosim/gz-tools/blob/gz-tools2/src/gz.in). It's the tool that aggregates all of the commands available from all the Gazebo libraries. There's an effort to use binary executables (https://github.com/gazebosim/gz-tools/issues/7) for this, but we have a ways to go.

christophfroehlich commented 4 months ago

Ok, thanks for the explanation.