Editable install

[henryiii]

The first step is to support a persistent build directory (done in 0.2). However, I could possibly implement this the slow way (always rebuild) as an experiment before implementing it properly with a static build directory, if that is a simpler order. (One problem with a static build directory is the virtualenv moves around, so the paths change).

[henryiii]

Persistent build dir work step 1

1. Source dir

This is the first error:

CMake Error: The source "/private/var/folders/_8/xtbws09n017fbzdx9dmgnyyr0000gn/T/build-via-sdist-q5x52ag6/cmake-example-0.0.1/CMakeLists.txt" does not match the source "/private/var/folders/_8/xtbws09n017fbzdx9dmgnyyr0000gn/T/build-via-sdist-4wn1l97i/cmake-example-0.0.1/CMakeLists.txt" used to generate cache.  Re-run cmake with a different source directory for now.

Build unpacks the SDist into a temporary directory since it's doing Source -> SDist -> Wheel. We could either try to fix this by patching the recorded paths, or we could detect this and wipe the build directory, or throw a nicer error. I think I'm in favor of wiping the build directory.

2. Build dir

If we just directly go to wheel, then Python discovery breaks. This is because we are setting the initial cache value without forcing it, so it gets the old cached value. There are two solutions - either we add "FORCE" to our initial cache file (which is not really "supported", but works in all CMake versions), or we rewrite the cache with the updated values. I'm probably going to start with the former since it's much easier to implement - @thewtex, @jcfr thoughts? Specifically, we are doing -CCMakeInit.txt and putting a set(... CACHE FORCE) in it instead of the "supported" (according to old mailing lists) set(... CACHE) command. But it's really just a normal CMake file that runs before the full file. My only worry is if this initial cache support is ever refactored to not support arbitrary CMake commands, it could start only supporting normal set commands. I don't need other arbitrary CMake code, but I do need FORCE.

Adding the FORCE does cause a direct source -> Wheel build to work with a reused build directory.

[jcfr]

Thanks for the detailed analysis🙏

I should be able to review in the next days 🚀

[LecrisUT]

Maybe should edit this issue to track what are the missing parts. I will copy the suggestion from spglib:

• [ ] Add a CMAKE_INSTALL_RPATH pointing to the library dependencies. For this we can either:
  • Manually specify the paths of the librareis, e.g. tool.scikit-build.installed-library-path calculated relative to CMAKE_INSTALL_PREFIX
  • More advanced, use cmake-file-api to fetch the details of the cmake targets. In the pyproject.toml, we just add the target(s) that contains the python library binding and we navigate through the dependency targets, and adding those to the equivalent of tool.scikit-build.installed-library-path above
• [ ] Expose the cmake configurations that scikit-build-core uses as cmake-preset

[casperdcl]

Hacky work-around for now using in-place builds to run pytest: https://amypad.github.io/CuVec/contrib... Hopefully can be improved drastically 🤞😅