chore: use scikit-build-core for the build

.github/workflows/format.yml

@@ -32,9 +32,6 @@ jobs:
     - name: Add matchers
       run: echo "::add-matcher::$GITHUB_WORKSPACE/.github/matchers/pylint.json"
     - uses: pre-commit/[email protected]
-      with:
-        # Slow hooks are marked with manual - slow is okay here, run them too
-        extra_args: --hook-stage manual --all-files
 
   clang-tidy:
     # When making changes here, please also review the "Clang-Tidy" section

.gitignore

@@ -45,3 +45,8 @@ pybind11Targets.cmake
 .ipynb_checkpoints/
 tests/main.cpp
 CMakeUserPresents.json
+
+/Python
+/tmp*
+.ruby-version
+.*cache*/

.pre-commit-config.yaml

@@ -108,15 +108,6 @@ repos:
   - id: rst-directive-colons
   - id: rst-inline-touching-normal
 
-# Checks the manifest for missing files (native support)
-- repo: https://github.com/mgedmin/check-manifest
-  rev: "0.50"
-  hooks:
-  - id: check-manifest
-    # This is a slow hook, so only run this if --hook-stage manual is passed
-    stages: [manual]
-    additional_dependencies: [cmake, ninja]
-
 # Check for spelling
 # Use tools/codespell_ignore_lines_from_errors.py
 # to rebuild .codespell-ignore-lines

CMakeLists.txt

@@ -65,6 +65,13 @@ if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
 
   message(STATUS "CMake ${CMAKE_VERSION}")
 
+  if(DEFINED SKBUILD AND DEFINED $ENV{PYBIND11_GLOBAL_PREFIX})
+    message(
+      FATAL_ERROR
+        "PYBIND11_GLOBAL_PREFIX is not supported, use nox -s build_global or a pybind11-global SDist instead."
+    )
+  endif()
+
   if(CMAKE_CXX_STANDARD)
     set(CMAKE_CXX_EXTENSIONS OFF)
     set(CMAKE_CXX_STANDARD_REQUIRED ON)
@@ -248,6 +255,9 @@ elseif(USE_PYTHON_INCLUDE_DIR AND DEFINED PYTHON_INCLUDE_DIR)
 endif()
 
 if(PYBIND11_INSTALL)
+  if(DEFINED SKBUILD_PROJECT_NAME AND SKBUILD_PROJECT_NAME STREQUAL "pybind11_global")
+    install(DIRECTORY ${pybind11_INCLUDE_DIR}/pybind11 DESTINATION "${SKBUILD_HEADERS_DIR}")
+  endif()
   install(DIRECTORY ${pybind11_INCLUDE_DIR}/pybind11 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
   set(PYBIND11_CMAKECONFIG_INSTALL_DIR
       "${CMAKE_INSTALL_DATAROOTDIR}/cmake/${PROJECT_NAME}"
@@ -314,6 +324,17 @@ if(PYBIND11_INSTALL)
   install(FILES "${CMAKE_CURRENT_BINARY_DIR}/pybind11.pc"
           DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/pkgconfig/")
 
+  # When building a wheel, include __init__.py's for modules
+  # (see https://github.com/pybind/pybind11/pull/5552)
+  if(DEFINED SKBUILD_PROJECT_NAME AND SKBUILD_PROJECT_NAME STREQUAL "pybind11")
+    file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/empty")
+    file(TOUCH "${CMAKE_CURRENT_BINARY_DIR}/empty/__init__.py")
+    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/empty/__init__.py"
+            DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/")
+    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/empty/__init__.py"
+            DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/pkgconfig/")
+  endif()
+
   # Uninstall target
   if(PYBIND11_MASTER_PROJECT)
     configure_file("${CMAKE_CURRENT_SOURCE_DIR}/tools/cmake_uninstall.cmake.in"

docs/conf.py

@@ -69,9 +69,10 @@
 # built documents.
 
 # Read the listed version
-with open("../pybind11/_version.py") as f:
-    code = compile(f.read(), "../pybind11/_version.py", "exec")
-loc = {}
+version_file = DIR.parent / "pybind11/_version.py"
+with version_file.open(encoding="utf-8") as f:
+    code = compile(f.read(), version_file, "exec")
+loc = {"__file__": str(version_file)}
 exec(code, loc)
 
 # The full version, including alpha/beta/rc tags.

noxfile.py

@@ -7,6 +7,13 @@
 from __future__ import annotations
 
 import argparse
+import contextlib
+import os
+from pathlib import Path
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from collections.abc import Generator
 
 import nox
 
@@ -99,13 +106,46 @@ def make_changelog(session: nox.Session) -> None:
 @nox.session(reuse_venv=True, default=False)
 def build(session: nox.Session) -> None:
     """
-    Build SDists and wheels.
+    Build SDist and wheel.
     """
 
     session.install("build")
     session.log("Building normal files")
     session.run("python", "-m", "build", *session.posargs)
-    session.log("Building pybind11-global files (PYBIND11_GLOBAL_SDIST=1)")
-    session.run(
-        "python", "-m", "build", *session.posargs, env={"PYBIND11_GLOBAL_SDIST": "1"}
-    )
+
+
+@contextlib.contextmanager
+def preserve_file(filename: Path) -> Generator[str, None, None]:
+    """
+    Causes a file to be stored and preserved when the context manager exits.
+    """
+    old_stat = filename.stat()
+    old_file = filename.read_text(encoding="utf-8")
+    try:
+        yield old_file
+    finally:
+        filename.write_text(old_file, encoding="utf-8")
+        os.utime(filename, (old_stat.st_atime, old_stat.st_mtime))
+
+
+@nox.session(reuse_venv=True)
+def build_global(session: nox.Session) -> None:
+    """
+    Build global SDist and wheel.
+    """
+
+    installer = ["--installer=uv"] if session.venv_backend == "uv" else []
+    session.install("build", "tomlkit")
+    session.log("Building pybind11-global files")
+    pyproject = Path("pyproject.toml")
+    with preserve_file(pyproject):
+        newer_txt = session.run("python", "tools/make_global.py", silent=True)
+        assert isinstance(newer_txt, str)
+        pyproject.write_text(newer_txt, encoding="utf-8")
+        session.run(
+            "python",
+            "-m",
+            "build",
+            *installer,
+            *session.posargs,
+        )

pybind11/_version.py

@@ -1,5 +1,28 @@
+# This file will be replaced in the wheel with a hard-coded version. This only
+# exists to allow running directly from source without installing (not
+# recommended, but supported).
+
 from __future__ import annotations
 
+import re
+from pathlib import Path
+
+DIR = Path(__file__).parent.resolve()
+
+input_file = DIR.parent / "include/pybind11/detail/common.h"
+regex = re.compile(
+    r"""
+\#define \s+ PYBIND11_VERSION_MAJOR \s+ (?P<major>\d+) .*?
+\#define \s+ PYBIND11_VERSION_MINOR \s+ (?P<minor>\d+) .*?
+\#define \s+ PYBIND11_VERSION_PATCH \s+ (?P<patch>\S+)
+""",
+    re.MULTILINE | re.DOTALL | re.VERBOSE,
+)
+
+match = regex.search(input_file.read_text(encoding="utf-8"))
+assert match, "Unable to find version in pybind11/detail/common.h"
+__version__ = "{major}.{minor}.{patch}".format(**match.groupdict())
+
 
 def _to_int(s: str) -> int | str:
     try:
@@ -8,5 +31,4 @@ def _to_int(s: str) -> int | str:
         return s
 
 
-__version__ = "3.0.0.dev1"
 version_info = tuple(_to_int(s) for s in __version__.split("."))

pyproject.toml

@@ -1,25 +1,106 @@
 [build-system]
-requires = ["setuptools>=42", "cmake>=3.18", "ninja"]
-build-backend = "setuptools.build_meta"
+requires = ["scikit-build-core >=0.11.0"]
+build-backend = "scikit_build_core.build"
 
+[project]
+name = "pybind11"
+description = "Seamless operability between C++11 and Python"
+authors = [{name = "Wenzel Jakob", email = "[email protected]"}]
+license = "BSD-3-Clause"
+license-files = ["LICENSE"]
+readme = "README.rst"
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Intended Audience :: Developers",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+    "Topic :: Utilities",
+    "Programming Language :: C++",
+    "Programming Language :: Python :: 3 :: Only",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: Implementation :: PyPy",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: C++",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+]
+keywords = [
+    "C++11",
+    "Python bindings",
+]
+dynamic = ["version"]
+requires-python = ">=3.8"
 
-[tool.check-manifest]
-ignore = [
-    "tests/**",
-    "docs/**",
-    "tools/**",
-    "include/**",
-    ".*",
-    "pybind11/include/**",
-    "pybind11/share/**",
-    "CMakeLists.txt",
-    "noxfile.py",
+[project.urls]
+Homepage = "https://github.com/pybind/pybind11"
+Documentation = "https://pybind11.readthedocs.io/"
+"Bug Tracker" = "https://github.com/pybind/pybind11/issues"
+Discussions = "https://github.com/pybind/pybind11/discussions"
+Changelog = "https://pybind11.readthedocs.io/en/latest/changelog.html"
+Chat = "https://gitter.im/pybind/Lobby"
+
+[project.optional-dependencies]
+global = ["pybind11-global"]  # TODO: pin
+
+[project.scripts]
+pybind11-config = "pybind11.__main__:main"
+
+[project.entry-points."pipx.run"]
+pybind11 = "pybind11.__main__:main"
+
+[project.entry-points.pkg_config]
+pybind11 = "pybind11.share.pkgconfig"
+
+
+[tool.scikit-build]
+minimum-version = "build-system.requires"
+sdist.exclude = [
+  "/docs/**",
+  "/.**",
 ]
+wheel.install-dir = "pybind11"
+wheel.platlib = false
+
+[tool.scikit-build.cmake.define]
+BUILD_TESTING = false
+PYBIND11_NOPYTHON = true
+prefix_for_pc_file = "${pcfiledir}/../../"
+
+[tool.scikit-build.metadata.version]
+provider = "scikit_build_core.metadata.regex"
+input = "include/pybind11/detail/common.h"
+regex = '''(?sx)
+\#define \s+ PYBIND11_VERSION_MAJOR \s+ (?P<major>\d+) .*?
+\#define \s+ PYBIND11_VERSION_MINOR \s+ (?P<minor>\d+) .*?
+\#define \s+ PYBIND11_VERSION_PATCH \s+ (?P<patch>\S+)
+'''
+result = "{major}.{minor}.{patch}"
 
 # Can't use tool.uv.sources with requirements.txt
 [tool.uv]
 index-strategy = "unsafe-best-match"
 
+[[tool.scikit-build.generate]]
+path = "pybind11/_version.py"
+template = '''
+from __future__ import annotations
+
+
+def _to_int(s: str) -> int | str:
+    try:
+        return int(s)
+    except ValueError:
+        return s
+
+
+__version__ = "$version"
+version_info = tuple(_to_int(s) for s in __version__.split("."))
+'''
+
+
 [tool.mypy]
 files = ["pybind11"]
 python_version = "3.8"
@@ -28,7 +109,7 @@ enable_error_code = ["ignore-without-code", "redundant-expr", "truthy-bool"]
 warn_unreachable = true
 
 [[tool.mypy.overrides]]
-module = ["ghapi.*"]
+module = ["ghapi.*", "tomlkit"]  # tomlkit has types, but not very helpful
 ignore_missing_imports = true
 
 
@@ -45,10 +126,10 @@ messages_control.disable = [
   "protected-access",
   "missing-module-docstring",
   "unused-argument",  # covered by Ruff ARG
+  "consider-using-f-string", # triggers in _version.py incorrectly
 ]
 
 [tool.ruff]
-target-version = "py38"
 src = ["src"]
 
 [tool.ruff.lint]