Removing obsolete message generation.

[ghost]

VoxelGrid is part of the nav2_msgs package. Doesn't need to be in
costmap_2d.

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Basic Info

Info	Please fill out this column
Ticket(s) this addresses	#473
Primary OS tested on	Ubuntu
Robotic platform tested on	NA

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Description of contribution in a few bullet points

• I tried to reproduce Issues with rosidl generators [Urgent] #473 by building everything in one big workspace.
• PR Update dependencies exported by nav2_tasks. #474 failed for me due to a missing TF dependency that was apparently exported by nav2_tasks
• For removing the idl exports from nav2_tasks and nav2_costmap_2d fixed the problem.
• Costmap was exporting the VoxelGrid message but that was already part of nav2_msgs.

[SteveMacenski]

So costmap 2d actually did build correctly in the build farm on the last release, so I'm reluctant to change this without due cause this round in case it causes other up stream problems. I dont see anything here I would take issue with however

Edit: I'll let Matt decide what he wants to do here

[ghost]

This would affect packages that depend on costmap_2d rather than costmap_2d itself. I saw those same rosidl_default_generator errors because of this problem. For me, the package affected was costmap_queue.

My guess is we will see the problem come up again depending on exact build order. However, I'm OK with waiting on this if the build farm is passing at the moment.

[SteveMacenski]

You have a good point, approved

[SteveMacenski]

@crdelsey it looks like you deleted stuff in tasks that #474 is handling, can you revert those?

[ghost]

Ok. I've removed the nav2_tasks part of the changes. I'll add them back in a separate PR after Crystal.

[SteveMacenski]

@crdelsey go ahead and merge

[mkhansenbot]

@crdelsey - I approved this but then realized it doesn't remove the rosidl_default_generators from the nav2_tasks package, didn't we determine that's not used anymore?

@SteveMacenski - What's the status of the release, are you going to tag a 0.1.4 or how will these changes get pulled into the build farm?

[SteveMacenski]

@mkhansen-intel I'll wait until #477 is done since that will likely cause more issues if we don't resolve it beforehand. I'd rather get the bulk of the errors / all of them out of the way before trying again

[ghost]

@mkhansen-intel Steve asked that I remove the nav2_tasks part of this PR, I'm assuming to minimize risk since #474 fixed them for now. I was going to add them in a separate PR after release.

[ghost]

@SteveMacenski I think trying to prune back all the exported dependencies (#477) is risky for the upcoming release. For the most part, having extra dependencies doesn't hurt anything. It was just a problem for the IDL generators because we were exporting a dependency without actually generating the code/CMake files for it.

[SteveMacenski]

@crdelsey is there reason to believe that no other export dependencies would have a similar outcome? I haven't looked under the hood in what makes idl "special" so if the answer is that idl is "special" I'll just take your word on it

[SteveMacenski]

I just dont want to keep re-releasing if we didnt fix the underlying issue, if we have, I can do that this afternoon

[ghost]

IDL is special because there is a message generation step that creates source code and extra stuff in the package exports.

If that doesn't run because there are no messages, then we have the exports listed, but no actual files for the downstream package to import.

There is nothing else like that in ROS2 at the moment ... to the best of my knowledge.