py10x-fin-base-cxx (cxxfin import)

Native extension for py10x-fin-base. Dist name is py10x-fin-base-cxx; the import module remains cxxfin. Install py10x-fin-base (not this package directly). Built with pybind11 and scikit-build-core.

Architecture

• cxxfin.cpp — pybind11 module source; PYBIND11_MODULE name is cxxfin
• generate_stubs.py — post-build stub generation; promotes py10x_kernel to RTLD_GLOBAL before importing cxxfin so that BTraitable typeinfo is visible (macOS flat namespace requirement)
• Headers fetched from cxx10x at the exact git commit matching the installed py10x_kernel binary (version string contains the hash)

Subclassing py10x_kernel types

py10x_kernel is built with CXX_VISIBILITY_PRESET default so its vtables and typeinfo are exported. On import it promotes itself to RTLD_GLOBAL via dladdr + dlopen(RTLD_NOW | RTLD_GLOBAL | RTLD_NOLOAD), making its symbols visible to subsequently loaded extension modules. py10x_kernel must be imported before cxxfin — this holds in normal usage since it is always loaded as part of the py10x-core import chain.

Incremental, automatic rebuild

cxxfin on is automatically rebuilt on import cxxfin whenever the sources changed.

Clean rebuild

Needed when changing build structure, e.g. adding source files, editing CMakeLists.txt):

uv pip uninstall py10x-fin-base-cxx
rm -rf .venv/py10x-build/cxxfin
uv sync --reinstall-package py10x-fin-base-cxx

• uv pip uninstall py10x-fin-base-cxx — removes the editable finder from site-packages, which otherwise intercepts import cxxfin during stub generation and causes a circular rebuild failure
• rm -rf .venv/py10x-build/cxxfin — wipes the stale CMake cache
• uv sync --reinstall-package py10x-fin-base-cxx — rebuilds and reinstalls from scratch

Normal development (edit C++ source → run) does not require this; the editable rebuild fires automatically on import.

Debug build

cxxfin builds Release by default. For Debug build, set the build type via scikit-build-core's env override and re-run uv sync, for example:

SKBUILD_CMAKE_BUILD_TYPE=Debug uv sync --reinstall-package py10x-fin-base-cxx

The build type is fixed at sync time (baked into the editable install along with the build-dir), so switching is just another sync — SKBUILD_CMAKE_BUILD_TYPE=Debug uv sync --reinstall-package py10x-fin-base-cxx for Debug, plain uv sync --reinstall-package py10x-fin-base-cxx for Release. Because each type has its own tree under .venv/py10x-build/cxxfin/<Debug|Release>/, switching does not rebuild from scratch.