docs: add pybind11 example

[alvgaona]

This is an example of using Pixi to compile pybind11 modules and make them available to any Python interpreter.

1. It uses CMake to compile the C++ code.
2. scikit-build-core is the tool used in the example to generate the .whl files.
3. It leverages the build PyPI package to run the build task.

[Hofer-Julian]

Thank you for your PR!

The build took 3 minutes on my machine, which feels a bit long for 10 lines of C++ code. I haven't used pybind11 before, so I don't know if that is normal.

[alvgaona]

Thank you for your PR!

The build took 3 minutes on my machine, which feels a bit long for 10 lines of C++ code. I haven't used pybind11 before, so I don't know if that is normal.

@Hofer-Julian I'm not sure why that is. I think it's mainly due to scikit-build-core doing things 🫠 Happens on my Intel-based PC too.

[Hofer-Julian]

Maybe someone with more C++ experience like @baszalmstra or @wolfv could check it out as well

[alvgaona]

The composed command took 6.604s when I built it with CMake directly. So I'm pretty sure it's scikit-build-core.

[alvgaona]

2m 33.07s when running the full task on osx-64.

[alvgaona]

~17s with the --wheel flag. The task that takes too long is when it is ran with with the --sdist flag, which I think it's default.

By default, a source distribution (sdist) is built from {srcdir}
and a binary distribution (wheel) is built from the sdist.
This is recommended as it will ensure the sdist can be used
to build wheels.

Pass -s/--sdist and/or -w/--wheel to build a specific distribution.
If you do this, the default behavior will be disabled, and all
artifacts will be built from {srcdir} (even if you combine
-w/--wheel with -s/--sdist, the wheel will be built from {srcdir}).

[Hofer-Julian]

~17s with the --wheel flag. The task that takes too long is when it is ran with with the --sdist flag, which I think it's default.

Sounds to me like we should pass the --wheel flag then, since that's the interesting output in my opinion :)

[alvgaona]

~17s with the --wheel flag. The task that takes too long is when it is ran with with the --sdist flag, which I think it's default.

Sounds to me like we should pass the --wheel flag then, since that's the interesting output in my opinion :)

Yeah, generally you'd like --sdist to share it via repositories. You can do whatever in this case.

[alvgaona]

@Hofer-Julian fixed it. The sdist was including .pixi in the tarballed package which was causing to take minutes to finish, and by excluding it, it takes ~34s.

[Hofer-Julian]

Awesome! Let's bring it in then!

[beenje]

Hi! Just saw this PR. It's a nice example.

I wanted to mention that we also use scikit-build-core in one of our project (with boost).
I created an install task that runs pip to build and install the package in editable mode as defined here. It's still marked as experimental support but has been working well for us.

pixi run install builds and install the package.
It allows to work on the pure python part without re-installing. If you touch cpp files, you have to re-run the command.

You might find that useful.
I think it's more convenient during development than pixi run build + pip install ... that you have to re-run every time.
After it might depend on what you want and if your project is pure cpp or include python as well.

See https://gitlab.com/tango-controls/pytango/-/blob/develop/pixi.toml?ref_type=heads#L18