fix: resolve three CI build/runtime failures

- CMakeLists.txt aarch64: use -march=armv8-a instead of -march=native
  to avoid assembler errors in cp38 manylinux_aarch64 containers whose
  binutils don't recognise newer ARMv9.2+ extension flags

- CMakeLists.txt: translate PYTHON_EXECUTABLE -> Python_EXECUTABLE and
  set PYBIND11_FINDPYTHON ON so CMake FindPython honours the hint for
  free-threaded Python (cp314t-win32 "libraries not found" was caused
  by the hint being silently ignored)

- pyproject.toml: use pybind11<3 for Python<3.14, pybind11>=3.0.0 for
  Python>=3.14 (PEP 508 markers in [build-system].requires); pin
  global before-build to pybind11[global]<3; add cp314/cp314t override
  that installs pybind11[global]>=3.0.0 to fix macOS py3.14 segfault

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

Author: 3 people

python/CMakeLists.txt

@@ -12,14 +12,20 @@ elseif(DARWIN)
     SET(CMAKE_CXX_FLAGS "-Wno-int-in-bool-context")
     SET(CMAKE_CXX_FLAGS_DEBUG "-Wall")
 elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "aarch64")
-    SET(CMAKE_CXX_FLAGS "-march=native -Wno-int-in-bool-context")
+    SET(CMAKE_CXX_FLAGS "-march=armv8-a -Wno-int-in-bool-context")
     SET(CMAKE_CXX_FLAGS_DEBUG "-Wall")
 else()
     SET(CMAKE_CXX_FLAGS "-march=native -Wno-int-in-bool-context -mavx -mfma")
     SET(CMAKE_CXX_FLAGS_DEBUG "-Wall")
 endif()
 
 # dependencies
+# Translate old-style hint (passed by setup.py -DPYTHON_EXECUTABLE=...)
+# to new-style used by CMake FindPython
+if(DEFINED PYTHON_EXECUTABLE AND NOT DEFINED Python_EXECUTABLE)
+    set(Python_EXECUTABLE "${PYTHON_EXECUTABLE}")
+endif()
+set(PYBIND11_FINDPYTHON ON)
 find_package(pybind11)
 find_package(OpenMP)
 

python/pyproject.toml

@@ -2,7 +2,8 @@
 requires = [
     "setuptools>=42",
     "wheel",
-    "pybind11>=2.8.0,<3",
+    "pybind11>=2.8.0,<3; python_version < '3.14'",
+    "pybind11>=3.0.0; python_version >= '3.14'",
     "cmake>=3.12,<4",
     "packaging>=22",
     "numpy>=1.20"
@@ -27,7 +28,7 @@ test-command = "pytest {package}/pytest -v"
 before-test = "pip install lifelines \"pandas<2.0.0\" scipy scikit-learn"
 
 # install pybind11 for cmake
-before-build = "pip install pybind11[global]"
+before-build = "pip install 'pybind11[global]<3'"
 
 [tool.cibuildwheel.linux]
 archs = ["x86_64", "i686", "aarch64"]
@@ -54,3 +55,7 @@ before-test = "pip install lifelines \"pandas<2.0.0\" scipy scikit-learn \"jobli
 [[tool.cibuildwheel.overrides]]
 select = "cp312-* cp312t-* cp313-* cp313t-* cp314-* cp314t-*"
 before-test = "pip install lifelines pandas scipy scikit-learn"
+
+[[tool.cibuildwheel.overrides]]
+select = "cp314-* cp314t-*"
+before-build = "pip install 'pybind11[global]>=3.0.0'"