Pixi and ROS2 Jazzy

[taylorpool]

Hello,

This looks like an amazing project. I saw that there was a channel dedicated to ROS2 Humble. ROS2 Jazzy is the newest LTS version and represents a large step forward. What would it take for me to create a channel representing ROS2 Jazzy, or to add it to an existing channel?

Once again, thanks for all your great work!

[taylorpool]

Found the answer to my own question in the Robostack Paper: https://arxiv.org/pdf/2104.12910

[traversaro]

@traversaro sorry for a dumb question, but how do github repos (including IsabelParedes/ros-iron) correlate to what I see on https://prefix.dev/channels?

Not dumb at all, and given the lack of complete docs, asking questions is the best way to understand what's going on. Each GitHub repository stores the configuration files for vinca, the tool used to generate conda-build (and soon rattler-build) recipes from the rosdistro metadata. For each new commit in the repo, the GitHub Action https://github.com/RoboStack/ros-humble/blob/main/.github/workflows/main.yml checks for change in files, and generate new recipes if necessary on the buildbranch_<platform>, see for example the commit RoboStack/ros-humble@cd66bb0 in https://github.com/RoboStack/ros-humble/tree/buildbranch_linux . As part of the commit, a GitHub Action job is generated (for example in that commit is the file .github/workflows/linux.yml) that then runs and actually compiles the packages that then are uploaded over at https://anaconda.org/RoboStack-staging, see https://github.com/RoboStack/ros-humble/actions/runs/9616368683/job/26525724034 .

The channel https://anaconda.org/RoboStack-staging is then mirrored over at https://prefix.dev/channels/robostack-staging, but I am not familiar with that process, probably @wolfv knows more?

[AndBondStyle]

@traversaro that explains a lot, thank you. So if I want to start experimenting with ROS Iron packages, for example, I need to:

1. Fork a repo from IsabelParedes/ros-iron (or maybe create an fresh one with only necessary stuff)
2. Create a conda channel and API token for publishing
3. Make some changes and let CI do its thing

And then how do I get pixi to see and install those conda packages?

[wolfv]

Hi @AndBondStyle - sure we can also do that! :) It would probably be nice to have more complete documentation for the whole RoboStack stuff.

If you want to follow the more traditional way, you would create a "channel" on anaconda.org, and generate an API key there that you can use for uploading. The RoboStack repositories also need a second Github Token to be able to push the generated Github Actions workflows to a branch on the same repository (buildbranch_linux, buildbranch_win, etc.)

If you want to install the packages with pixi, you can just add:

channels = ["mychannel", "conda-forge"]

where mychannel would be the name of your channel. If the channel was on prefix.dev, then you would use ["https://prefix.dev/mychannel", ...] etc. - currently anaconda.org is the "default namespace".

[traversaro]

Yes, that is basically it, even if probably for debugging you may want to build locally for faster feedback loops. pixi by default can install packages from all conda channels from anaconda.org, even if they are not mirrored on prefix.dev (to do a check, you can install icub-basic-demos from the robotology channel, that is on anaconda but is is not mirrored in prefix.dev).

[wolfv]

Yes, when you build packages locally, you create a "local" conda channel (a conda channel is a directory with certani subdirectories). E.g.

output
 - osx-arm64
   - repodata.json
   - foo-1.2.3-hash.conda
 - linux-64 
   - repodata.json
 - noarch
   - repodata.json

So you can also point to /path/to/output in your pixi.toml and pixi should find the local packages.