refactor the build approach

.github/workflows/ci.yaml

@@ -20,13 +20,12 @@ jobs:
         python-version: '3.10'
     - name: Build and Install
       run: |
-        ${Python3_EXECUTABLE} -m pip install pybind11
-        ${Python3_EXECUTABLE} -m pip install pytest
-        ${Python3_EXECUTABLE} -m pip install numpy
-        ${Python3_EXECUTABLE} -m pip install --verbose .
+        python3 -m pip install pybind11
+        python3 -m pip install pytest
+        python3 -m pip install --verbose .
 
     - name: Test
       run: |
         source .venv/bin/activate
         export LD_LIBRARY_PATH="/opt/drake/lib:$LD_LIBRARY_PATH"
-        ${Python3_EXECUTABLE} -m pytest
+        python3 -m pytest

CMakeLists.txt

@@ -11,31 +11,6 @@ project(
   VERSION ${SKBUILD_PROJECT_VERSION}
   LANGUAGES CXX)
 
-
-if (NOT SKBUILD)
-  message(WARNING "\
-  This CMake file is meant to be executed using 'scikit-build'. Running
-  it directly will almost certainly not produce the desired result. If
-  you are a user trying to install this package, please use the command
-  below, which will install all necessary build dependencies, compile
-  the package in an isolated environment, and then install it.
-  =====================================================================
-   $ pip install .
-  =====================================================================
-  If you are a software developer, and this is your own package, then
-  it is usually much more efficient to install the build dependencies
-  in your environment once and use the following command that avoids
-  a costly creation of a new virtual environment at every compilation:
-  =====================================================================
-   $ pip install nanobind scikit-build-core[pyproject]
-   $ pip install --no-build-isolation -ve .
-  =====================================================================
-  You may optionally add -Ceditable.rebuild=true to auto-rebuild when
-  the package is imported. Otherwise, you need to re-run the above
-  after editing C++ files.")
-endif()
-
-
 include(CTest)
 
 find_package(drake CONFIG REQUIRED)

pyproject.toml

@@ -1,6 +1,11 @@
 [build-system]
-requires = ["scikit-build-core>=0.3.3", "pybind11"]
-build-backend = "scikit_build_core.build"
+requires = [
+    "setuptools>=42",
+    "wheel",
+    "ninja",
+    "cmake>=3.12",
+]
+build-backend = "setuptools.build_meta"
 
 [project]
 name = "drake_extension"
@@ -21,11 +26,6 @@ test = ["pytest"]
 [project.urls]
 Homepage = "https://github.com/MAminSFV/drake_extension"
 
-
-[tool.scikit-build]
-wheel.expand-macos-universal-tags = true
-
-
 [tool.pytest.ini_options]
 minversion = "6.0"
 addopts = ["-ra", "--showlocals", "--strict-markers", "--strict-config"]
@@ -42,6 +42,7 @@ testpaths = ["tests"]
 build-frontend = "build[uv]"
 test-command = "pytest {project}/tests"
 test-extras = ["test"]
+before-build = "rm -rf {project}/build"
 
 [tool.cibuildwheel.pyodide]
 environment.CFLAGS = "-fexceptions"
@@ -50,6 +51,7 @@ build-frontend = {name = "build", args = ["--exports", "whole_archive"]}
 
 [tool.ruff]
 src = ["src"]
+target-version = "py310"
 
 [tool.ruff.lint]
 extend-select = [

scripts/setup_ubuntu

@@ -12,8 +12,7 @@ apt-get install --no-install-recommends -y $(cat <<EOF
   gnupg
   cmake
   lsb-release
-  python3-pip
-  python3-venv
+  python3-dev
   locales
 EOF
 )

setup.py

@@ -0,0 +1,112 @@
+import os
+import re
+import subprocess
+import sys
+from pathlib import Path
+
+from setuptools import Extension, setup
+from setuptools.command.build_ext import build_ext
+
+
+# A CMakeExtension needs a sourcedir instead of a file list.
+# The name must be the _single_ output extension from the CMake build.
+# If you need multiple extensions, see scikit-build.
+class CMakeExtension(Extension):
+    def __init__(self, name: str, sourcedir: str = "") -> None:
+        super().__init__(name, sources=[])
+        self.sourcedir = os.fspath(Path(sourcedir).resolve())
+
+
+class CMakeBuild(build_ext):
+    def build_extension(self, ext: CMakeExtension) -> None:
+        # Must be in this form due to bug in .resolve() only fixed in Python 3.10+
+        ext_fullpath = Path.cwd() / self.get_ext_fullpath(ext.name)
+        extdir = ext_fullpath.parent.resolve()
+
+        # Using this requires trailing slash for auto-detection & inclusion of
+        # auxiliary "native" libs
+
+        debug = int(os.environ.get("DEBUG", 0)) if self.debug is None else self.debug
+        cfg = "Debug" if debug else "Release"
+
+        # CMake lets you override the generator - we need to check this.
+        # Can be set with Conda-Build, for example.
+        cmake_generator = os.environ.get("CMAKE_GENERATOR", "")
+
+        # Set Python_EXECUTABLE instead if you use PYBIND11_FINDPYTHON
+        # EXAMPLE_VERSION_INFO shows you how to pass a value into the C++ code
+        # from Python.
+        cmake_args = [
+            f"-DCMAKE_LIBRARY_OUTPUT_DIRECTORY={extdir}{os.sep}",
+            f"-DPYTHON_EXECUTABLE={sys.executable}",
+            f"-DCMAKE_BUILD_TYPE={cfg}",  # not used on MSVC, but no harm
+        ]
+        build_args = []
+        # Adding CMake arguments set as environment variable
+        # (needed e.g. to build for ARM OSx on conda-forge)
+        if "CMAKE_ARGS" in os.environ:
+            cmake_args += [item for item in os.environ["CMAKE_ARGS"].split(" ") if item]
+
+        # In this example, we pass in the version to C++. You might not need to.
+        cmake_args += [f"-DEXAMPLE_VERSION_INFO={self.distribution.get_version()}"]
+
+        if self.compiler.compiler_type != "msvc":
+            # Using Ninja-build since it a) is available as a wheel and b)
+            # multithreads automatically. MSVC would require all variables be
+            # exported for Ninja to pick it up, which is a little tricky to do.
+            # Users can override the generator with CMAKE_GENERATOR in CMake
+            # 3.15+.
+            if not cmake_generator or cmake_generator == "Ninja":
+                try:
+                    import ninja
+
+                    ninja_executable_path = Path(ninja.BIN_DIR) / "ninja"
+                    cmake_args += [
+                        "-GNinja",
+                        f"-DCMAKE_MAKE_PROGRAM:FILEPATH={ninja_executable_path}",
+                    ]
+                except ImportError:
+                    pass
+
+        if sys.platform.startswith("darwin"):
+            # Cross-compile support for macOS - respect ARCHFLAGS if set
+            archs = re.findall(r"-arch (\S+)", os.environ.get("ARCHFLAGS", ""))
+            if archs:
+                cmake_args += ["-DCMAKE_OSX_ARCHITECTURES={}".format(";".join(archs))]
+
+        # Set CMAKE_BUILD_PARALLEL_LEVEL to control the parallel build level
+        # across all generators.
+        if "CMAKE_BUILD_PARALLEL_LEVEL" not in os.environ:
+            # self.parallel is a Python 3 only way to set parallel jobs by hand
+            # using -j in the build_ext call, not supported by pip or PyPA-build.
+            if hasattr(self, "parallel") and self.parallel:
+                # CMake 3.12+ only.
+                build_args += [f"-j{self.parallel}"]
+
+        build_temp = Path(self.build_temp) / ext.name
+        if not build_temp.exists():
+            build_temp.mkdir(parents=True)
+
+        subprocess.run(
+            ["cmake", ext.sourcedir, *cmake_args], cwd=build_temp, check=True
+        )
+        subprocess.run(
+            ["cmake", "--build", ".", *build_args], cwd=build_temp, check=True
+        )
+
+
+# The information here can also be placed in setup.cfg - better separation of
+# logic and declaration, and simpler if you include description/version in a file.
+setup(
+    name="drake_extension",
+    version="0.0.1",
+    author="M. Amin Safavi",
+    author_email="[email protected]",
+    description="A test project using pybind11 and Drake",
+    long_description="",
+    ext_modules=[CMakeExtension("drake_extension")],
+    cmdclass={"build_ext": CMakeBuild},
+    zip_safe=False,
+    extras_require={"test": ["pytest>=6.0"]},
+    python_requires=">=3.10",
+)

tests/test_simple_adder.py

@@ -1,5 +1,5 @@
-import numpy as np
-#from drake_extension import SimpleAdder
+#import numpy as np
+from drake_extension import SimpleAdder
 
 from pydrake.systems.analysis import Simulator
 from pydrake.systems.framework import (