docs: initial addition of ros2 tutorial #1116

ruben-arts · 2024-04-04T11:51:09Z

This is an initial try to make a simple tutorial. I feel it could be heavily extended but it feels hard to do it in steps. Input is very much appreciated.

Test this PR by running:

pixi run docs

And then open http://127.0.0.1:8000/pixi/tutorials/ros2/

docs/tutorials/ros2.md

Co-authored-by: Silvio Traversaro <[email protected]>

docs/tutorials/ros2.md

traversaro · 2024-04-04T13:12:41Z

docs/tutorials/ros2.md

+Normally this would be the script you add to your `.bashrc` but now you tell pixi to use it.
+
+```toml title="pixi.toml"
+[activation]
+scripts = ["install/setup.sh"]
+```


This part is the only one that does not works on Windows, probably we want to mention at the beginning of the tutorial that the tutorial does not work on Windows.

I improved the story to include the multi platform work.

Co-authored-by: Silvio Traversaro <[email protected]>

traversaro · 2024-04-04T14:23:57Z

Really cool! I see the point of showing the use pixi run ros2 run and the tasks system, but as this may be the first exposure to pixi for ROS 2 users, I would also mention somewhere of the existence of pixi shell, even just with those box that can be expanded.

Probably it is a bit out of scope, but one thing that we may want to at least warn the user about is rosdep . If one wanted to use rosdep, what would happen is that rosdep would call conda install, and I am not sure what would happen at that point in the pixi environment. I guess it may be possible to modify rosdep to actually call pixi add, but that is probably another story.

ruben-arts · 2024-04-04T14:48:26Z

Thank you for the input @traversaro! Will update it!

traversaro · 2024-04-05T07:36:53Z

docs/tutorials/ros2.md

+To build a C++ node you need to add the `ament_cmake` and some other build dependencies to your manifest file.
+```shell
+pixi add ros-humble-ament-cmake-auto compilers pkg-config cmake
+pixi add gcc_linux-64 gxx_linux-64 make -p linux-64


Why do you need to install manually gcc_linux-64 and gxx_linux-64 , shouldn't those be installed by compilers ?

Yeah that's a mistake! Let me fix that. Still need to test on more platforms.

Good point. Probably you also need to add make on all non-windows platform. To be honest, I typically install both make and ninja also on Windows just to avoid confusion. I think it would be useful to eventually add a build-essential or build-essential-cpp meta-package to conda-forge that depends on compilers and all these tools (perhaps even meson), but I never put the effort to start a discussion on this.

Good idea, that would help to get started with conda.

traversaro · 2024-04-05T07:39:40Z

Probably it is a bit out of scope, but one thing that we may want to at least warn the user about is rosdep . If one wanted to use rosdep, what would happen is that rosdep would call conda install, and I am not sure what would happen at that point in the pixi environment. I guess it may be possible to modify rosdep to actually call pixi add, but that is probably another story.

Just for alignment, to add rosdep support for pixi the required modifications are not so many:

(the PR are not merged but we have them integrated as patches in the conda-forge corresponding packages, see https://github.com/conda-forge/rosdep-feedstock/blob/d3a72b237c86299d398f0f552eb3623fe95dba64/recipe/810.patch)

docs: initial addition of ros2 tutorial

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