moveit_servo: Warning points user to non-working intra-process communication

[SammyRamone]

Description

If moveit_servo is started it will give the following warning: Intra-process communication is disabled, consider enabling it by adding: extra_arguments=[{'use_intra_process_comms' : True}] to the Servo composable node in the launch file moveit_servo.servo_node Naturally, one is inclined to enable this after reading this warning. However, this will lead to the following error: Component constructor threw an exception: intraprocess communication is not allowed with a zero qos history depth value

Therefore, I think that this warning is currently very misleading.

This issue has already been discussed in https://github.com/ros-planning/moveit2/pull/722 where the intra-process communication was removed by @tylerjw to resolve this bug. @henningkayser already proposed to also remove this warning. However, this was not done.

I propose to remove/disable the warning for now and to open another issue about allowing intra-process communication in MoveIt2, (which is currently blocked by some QoS settings). I also did a quick search if I can find the where this use of a zero history depth qos happens, but I did not find anything in the moveit code.

Your environment

• ROS Distro: Rolling
• OS Version: Ubuntu 22.04
• Source build 2.8.0
• Cyclone DDS

Steps to reproduce

Launch moveit_servo as a ComposableNode.

Expected behaviour

Either no warning that the intra-process communication is not used or that the node works when intra-process communication is enabled.

Actual behaviour

Following advice of the warning leads to an error.

[ibrahiminfinite]

@sea-bass Did you guys come across this error ? I don't remember testing this during the refactor, so this is probably something that was missed.

[sea-bass]

I recall seeing that warning when testing, and am OK with the fix in #722 to not enable it.

It likely cropped up in rolling later than your refactor, so it's possible it was missed because it wasn't there at the time!

[henningkayser]

@SammyRamone would you mind filing a PR to fix this? ;)

[SammyRamone]

@SammyRamone would you mind filing a PR to fix this? ;)

I can do that, but it will take some time since I will be busy till end of february

[SammyRamone]

@henningkayser I opened a PR in https://github.com/ros-planning/moveit2/pull/2752