scikit-build-core appears to work

Next step is to add a yml using cibuildwheel, and then we can flesh out the tests

.gitignore

@@ -5,6 +5,7 @@ install/
 build/
 include/
 !c/include/
+!python/pybind11/include/
 lib/
 mod/
 
@@ -227,3 +228,6 @@ cython_debug/
 
 # Mac files
 .DS_Store
+
+# Version file
+_version.txt

CMakeLists.txt

@@ -64,21 +64,33 @@ endif ()
 
 # Get the version number
 find_package(Git)
+set(IS_REPO FALSE)
 if(GIT_EXECUTABLE)
   # --always means git describe will output the commit hash if no tags are found
   # This is usually the case for forked repos since they do not clone tags by default.
   execute_process(COMMAND ${GIT_EXECUTABLE} describe --tags --always --dirty
     WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
     OUTPUT_VARIABLE PRIMA_VERSION
-    OUTPUT_STRIP_TRAILING_WHITESPACE)
-else()
-  # If git is not available, that may indicate we are building on macports which
-  # downloads the bundle from github (which uses git archive) and so the version
-  # number should be in .git-archival.txt
-  file(STRINGS .git-archival.txt PRIMA_VERSION)
-  if(PRIMA_VERSION MATCHES "describe")
-    message(WARNING "No git detected and .git-archival.txt does not contain a version number")
-    set(PRIMA_VERSION "unknown")
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    RESULT_VARIABLE GIT_RESULT ERROR_QUIET)
+  if (GIT_RESULT EQUAL 0)
+    set(IS_REPO TRUE)
+  endif()
+endif()
+if(NOT GIT_EXECUTABLE OR NOT IS_REPO)
+  # If git is not available, or this isn't a repo, that may indicate we are building
+  # on macports which downloads the bundle from github (which uses git archive) and
+  # so the version number should be in .git-archival.txt.
+  # Alternatively it might mean that we're building the Python bindings, in which case
+  # the version is output in _version.txt. I know, it's complicated. I don't make the rules.
+  if(EXISTS _version.txt)
+    file(STRINGS _version.txt PRIMA_VERSION)
+  else()
+    file(STRINGS .git-archival.txt PRIMA_VERSION)
+    if(PRIMA_VERSION MATCHES "describe")
+      message(WARNING "No git detected and .git-archival.txt does not contain a version number")
+      set(PRIMA_VERSION "unknown")
+    endif()
   endif()
 
 endif()

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["scikit-build-core", "pybind11", "numpy"]
+requires = ["scikit-build-core", "numpy"]
 build-backend = "scikit_build_core.build"
 
 [project]
@@ -8,17 +8,10 @@ dependencies = ["numpy"]
 dynamic = ["version"]
 
 [tool.scikit-build]
-cmake.targets = ["prima_pybind"]
-
-
-# VERSION OPTION 1
-# [tool.scikit-build.metadata.version]
-# provider = "scikit_build_core.metadata.regex"
-# input = "VERSION.txt"
-# regex = '(?P<value>[0-9.]+)'
-# VERSION OPTION 2
+cmake.targets = ["_prima"]
 metadata.version.provider = "scikit_build_core.metadata.setuptools_scm"
-sdist.include = ["pyVERSION.txt"]
+sdist.include = [".git-archival.txt"]
+install.components = ["Prima_Python_C_Extension"]
+
 [tool.setuptools_scm]  # Section required
-version_file = "pyVERSION.txt"
-# END VERSION OPTIONS
+version_file = "_version.txt"

python/CMakeLists.txt

@@ -17,35 +17,32 @@ if (NOT _IMPORT_NUMPY EQUAL 0)
   return()
 endif ()
 
-# This section is cribbed from scipy/meson.build
-if(WIN32 AND (CMAKE_C_COMPILER_ID MATCHES "GNU"))
-  message("MinGW detected, adding compiler and linker flags")
-  add_link_options(-lucrt -static)
-  set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mlong-double-64 -D__USE_MINGW_ANSI_STDIO=1")
-  set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__USE_MINGW_ANSI_STDIO=1")
-endif()
-
-if (WIN32)
-  set (PYTHON_SITE_PACKAGES Lib/site-packages)
-else ()
-  set (PYTHON_SITE_PACKAGES ${CMAKE_INSTALL_LIBDIR}/python${Python_VERSION_MAJOR}.${Python_VERSION_MINOR}/site-packages)
-endif ()
 
+set(PYBIND11_NEWPYTHON ON)
 add_subdirectory(pybind11)
 pybind11_add_module(_prima _prima.cpp)
 target_include_directories(_prima PRIVATE ${CMAKE_SOURCE_DIR}/c/include)
 target_link_libraries(_prima PRIVATE primac primaf)
 target_compile_definitions(_prima PRIVATE VERSION_INFO=${PRIMA_VERSION})
 
-install (TARGETS _prima DESTINATION ${PYTHON_SITE_PACKAGES}/prima/)
-install (FILES __init__.py DESTINATION ${PYTHON_SITE_PACKAGES}/prima/)
-install (FILES _nlconstraints.py DESTINATION ${PYTHON_SITE_PACKAGES}/prima/)
-install (FILES _linearconstraints.py DESTINATION ${PYTHON_SITE_PACKAGES}/prima/)
-install (FILES _bounds.py DESTINATION ${PYTHON_SITE_PACKAGES}/prima/)
+# This section is cribbed from scipy/meson.build
+if(WIN32 AND (CMAKE_C_COMPILER_ID MATCHES "GNU"))
+  message(STATUS "MinGW detected, adding compiler and linker flags")
+  target_link_options(_prima PUBLIC -lucrt -static)
+  target_compile_options(_prima PUBLIC $<$<COMPILE_LANGUAGE:C>:-mlong-double-64 -D__USE_MINGW_ANSI_STDIO=1>)
+  target_compile_options(_prima PUBLIC $<$<COMPILE_LANGUAGE:CXX>:-D__USE_MINGW_ANSI_STDIO=1>)
+endif()
+
+install (TARGETS _prima DESTINATION prima/ COMPONENT Prima_Python_C_Extension)
+# The following are not added to the component because scikit-build-core automatically
+# detects files in python/<package_name> and adds them to the wheel. These commands
+# are here in case one is building via cmake directory and not via scikit-build-core
+file(GLOB SUPPORTING_PY_FILES "${CMAKE_CURRENT_SOURCE_DIR}/prima/*.py")
+install (FILES ${SUPPORTING_PY_FILES} DESTINATION prima)
 
 macro (prima_add_py_test name)
-  add_test (NAME example_${name}_python COMMAND ${Python_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/examples/example_${name}.py)
-  set_tests_properties (example_${name}_python PROPERTIES ENVIRONMENT "PYTHONPATH=${CMAKE_INSTALL_PREFIX}/${PYTHON_SITE_PACKAGES}")
+  add_test (NAME example_${name}_python COMMAND ${Python_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/examples/${name}_example.py)
+  # set_tests_properties (example_${name}_python PROPERTIES ENVIRONMENT "PYTHONPATH=${CMAKE_INSTALL_PREFIX}/${PYTHON_SITE_PACKAGES}")
   if (WIN32)
     file(TO_NATIVE_PATH "${PROJECT_BINARY_DIR}/bin" _BIN_PATH)
     set_property(TEST example_${name}_python APPEND PROPERTY ENVIRONMENT "PATH=${_BIN_PATH}\\;$ENV{PATH}")
@@ -66,6 +63,6 @@ add_test (NAME python-tests
   COMMAND ${Python_EXECUTABLE} -m pytest --capture=no
   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/tests
 )
-set_tests_properties(python-tests
-    PROPERTIES ENVIRONMENT "PYTHONPATH=${CMAKE_INSTALL_PREFIX}/${PYTHON_SITE_PACKAGES}")
+#set_tests_properties(python-tests
+    #PROPERTIES ENVIRONMENT "PYTHONPATH=${CMAKE_INSTALL_PREFIX}/${PYTHON_SITE_PACKAGES}")
 

python/__init__.py → python/prima/__init__.py

@@ -1,4 +1,4 @@
-from ._prima import minimize as _minimize
+from ._prima import minimize as _minimize, __version__
 from ._nlconstraints import NonlinearConstraint, process_single_nl_constraint, process_multiple_nl_constraints
 from ._linearconstraints import LinearConstraint, process_single_linear_constraint, process_multiple_linear_constraints
 from ._bounds import process_bounds