Plan for ROS2 Jazzy?

[thomasegriffith]

Hi,

Is there any plan to enable ROS2 Jazzy (the next LTS release after Humble)? If so, what would that entail?

Thanks!

[ahans]

I'm not aware of any plan, but would be interested in support for Jazzy myself as well. From my perspective, it would work like this:

1. Update the ros2 repository to point at the newer release. This only pulls the ros2.repos file with all the versions of the repositories that go into a release.
2. Run the updater script to update all the repositories in rules_ros2: bazel run //repositories/private:resolver
3. See what breaks and fix it.

I already did step 1 and 2. As expected, quite a few things have changed and so the breakage is significant. Local patches cannot be applied anymore, some include files have changed, etc. Looks like quite some effort to get this working, but certainly doable. It could probably be parallelized to some extent.

However, instead of switching rules_ros2 over to Jazzy completely, I would very much prefer supporting both, Humble and Jazzy, from the same main branch. But I'm not sure if that's realistic, especially if WORKSPACE and bzlmod should be kept alive at the same time as well.

[lalten]

Another complication/benefit would be bumping the Python interpreter to 3.12, which is the Ubuntu 24.04 Noble (Jazzy's tier 1 platform) default.

[lalten]

One pattern that may work for supporting different ROS distros/versions is to use an extension to generate the repos from some lockfile in Starlark instead of using the resolver tool to generate the BUILD. Example: https://github.com/lalten/rules_cpan/blob/main/cpan/install.bzl. There could be some default/tested-to-work lockfiles that correspond to the latest Humble, Jazzy, ...

[ahans]

That sounds like an interesting approach. I guess it would also allow for simultaneous support of bzlmod and WORKSPACE. For the latter instead of an extension we would just have a repository rule that users would have to call from their WORKSPACE file.

[thomasegriffith]

I already did step 1 and 2. As expected, quite a few things have changed and so the breakage is significant. Local patches cannot be applied anymore, some include files have changed, etc. Looks like quite some effort to get this working, but certainly doable. It could probably be parallelized to some extent.

Ditto... also looked into this and came away with the same realizations. It seemed a few of the local patches still worked, but others were very broken.

Agreed that supporting both Humble and Jazzy would be preferable.

[mvukov]

I suspect the most critical changes are to get IDL code generation working (patching official generator code and templates). Then there was a patch or two for the plugin system. Besides that, we have a number of other patches in the repo to maybe fix.

When we moved from foxy to humble, I cut feature/foxy branch just before humble-related changes were merged to main. The idea was that we could backport changes (never happened for foxy branch). With my current bandwidth, I'd support one ROS 2 LTS release in this repo as is the situation today. Meaning if we move to jazzy, there would be a feature/humble branch for possible fixes. If something more is needed, like more than one ROS release working in this repo, more people will need to get involved.

So far I thought about this upgrade, but my free time is somewhat limited these days. On the other hand, I'd gladly review a PR in this direction. If something sooner is needed, get in touch.

[thomasegriffith]

Thanks! Not sure I have anything that's immediately pressing, but will get in touch when I do.

[mvukov]

FWIW, there is #558 -- the whole repo has been updated to jazzy and python 3.12 by default.