feat: SDist CMake option (#454)

Working on #392.

- [x] Add to setuptools build_meta, too

For later PR:

```diff
+    libpl = sysconfig.get_config_var("LIBPL")
+    library = sysconfig.get_config_var("LIBRARY")
+
+    if libpl and library and Path(libpl).joinpath(library).is_file():
+        assert isinstance(libpl, str)
+        assert isinstance(library, str)
+        return Path(libpl) / library
```

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

Author: henryiii

README.md

@@ -178,6 +178,9 @@ sdist.exclude = []
 # value if not set.
 sdist.reproducible = true
 
+# If set to True, CMake will be run before building the SDist.
+sdist.cmake = false
+
 # A list of packages to auto-copy into the wheel. If this is not set, it will
 # default to the first of ``src/<package>`` or ``<package>`` if they exist. The
 # prefix(s) will be stripped from the package name inside the wheel.
@@ -195,9 +198,11 @@ wheel.py-api = ""
 # (before 21.0.1) find the correct wheel.
 wheel.expand-macos-universal-tags = false
 
-# The install directory for the wheel. This is relative to the platlib root.
-# EXPERIMENTAL: An absolute path will be one level higher than the platlib root,
-# giving access to "/platlib", "/data", "/headers", and "/scripts".
+# The install directory for the wheel. This is relative to the platlib root. You
+# might set this to the package name. The original dir is still at
+# SKBUILD_PLATLIB_DIR (also SKBUILD_DATA_DIR, etc. are available). EXPERIMENTAL:
+# An absolute path will be one level higher than the platlib root, giving access
+# to "/platlib", "/data", "/headers", and "/scripts".
 wheel.install-dir = ""
 
 # A list of license files to include in the wheel. Supports glob patterns.

docs/configuration.md

@@ -152,6 +152,52 @@ reproducible builds if you prefer, however:
 sdist.reproducible = false
 ```
 
+You can also request CMake to run during this step:
+
+```toml
+[tool.scikit-build]
+sdist.cmake = true
+```
+
+:::{note}
+
+If you do this, you'll want to have some artifact from the configure in your
+source directory; for example:
+
+```cmake
+include(FetchContent)
+
+if(NOT SKBUILD_STATE STREQUAL "sdist"
+   AND EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/pybind11/CMakeLists.txt")
+  message(STATUS "Using integrated pybind11")
+  set(FETCHCONTENT_FULLY_DISCONNECTED ON)
+endif()
+
+FetchContent_Declare(
+  pybind11
+  GIT_REPOSITORY https://github.com/pybind/pybind11.git
+  GIT_TAG v2.11.1
+  SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/pybind11)
+
+set(PYBIND11_FINDPYTHON ON)
+FetchContent_MakeAvailable(pybind11)
+```
+
+The `/pybind11` directory is in the `.gitignore` and important parts are in
+`sdist.include`:
+
+```toml
+[tool.scikit-build]
+sdist.cmake = true
+sdist.include = [
+  "pybind11/tools",
+  "pybind11/include",
+  "pybind11/CMakeLists.txt",
+]
+```
+
+:::
+
 ## Customizing the built wheel
 
 The wheel will automatically look for Python packages at `<package_name>` and

noxfile.py

@@ -10,7 +10,15 @@
 
 DIR = Path(__file__).parent.resolve()
 
-nox.options.sessions = ["lint", "pylint", "tests"]
+nox.options.sessions = [
+    "lint",
+    "pylint",
+    "generate_schema",
+    "readme",
+    "build_api_docs",
+    "tests",
+    "test_doc_examples",
+]
 
 
 @nox.session(reuse_venv=True)

src/scikit_build_core/build/__init__.py

@@ -104,9 +104,15 @@ def get_requires_for_build_sdist(
 
     requires = GetRequires(config_settings)
 
+    # These are only injected if cmake is required for the SDist step
+    cmake_requires = (
+        [*requires.cmake(), *requires.ninja()] if requires.settings.sdist.cmake else []
+    )
+
     return [
         "pathspec",
         "pyproject_metadata",
+        *cmake_requires,
         *requires.dynamic_metadata(),
     ]
 

src/scikit_build_core/build/sdist.py

@@ -18,6 +18,7 @@
 from ..settings.skbuild_read_settings import SettingsReader
 from ._file_processor import each_unignored_file
 from ._init import setup_logging
+from .wheel import _build_wheel_impl
 
 __all__: list[str] = ["build_sdist"]
 
@@ -110,6 +111,11 @@ def build_sdist(
     srcdirname = f"{sdist_name}-{metadata.version}"
     filename = f"{srcdirname}.tar.gz"
 
+    if settings.sdist.cmake:
+        _build_wheel_impl(
+            None, config_settings, None, exit_after_config=True, editable=False
+        )
+
     sdist_dir.mkdir(parents=True, exist_ok=True)
     with contextlib.ExitStack() as stack:
         gzip_container = stack.enter_context(

src/scikit_build_core/build/wheel.py

@@ -71,6 +71,7 @@ def _build_wheel_impl(
     config_settings: dict[str, list[str] | str] | None,
     metadata_directory: str | None,
     *,
+    exit_after_config: bool = False,
     editable: bool,
 ) -> WheelImplReturn:
     """
@@ -97,6 +98,8 @@ def _build_wheel_impl(
     action = "editable" if editable else "wheel"
     if wheel_directory is None:
         action = f"metadata_{action}"
+    if exit_after_config:
+        action = "sdist"
 
     cmake = CMake.default_search(minimum_version=settings.cmake.minimum_version)
 
@@ -176,7 +179,7 @@ def _build_wheel_impl(
             config=config,
         )
 
-        if wheel_directory is None:
+        if wheel_directory is None and not exit_after_config:
             if metadata_directory is None:
                 msg = "metadata_directory must be specified if wheel_directory is None"
                 raise AssertionError(msg)
@@ -209,6 +212,11 @@ def _build_wheel_impl(
             version=metadata.version,
         )
 
+        if exit_after_config:
+            return WheelImplReturn("")
+
+        assert wheel_directory is not None
+
         generator = builder.config.env.get(
             "CMAKE_GENERATOR",
             "MSVC"

src/scikit_build_core/builder/get_requires.py

@@ -19,6 +19,7 @@
 )
 from ..resources import resources
 from ..settings._load_provider import load_provider
+from ..settings.skbuild_model import ScikitBuildSettings
 from ..settings.skbuild_read_settings import SettingsReader
 
 __all__ = ["GetRequires"]
@@ -48,8 +49,12 @@ def __post_init__(self) -> None:
             "pyproject.toml", self.config_settings
         ).settings
 
+    @property
+    def settings(self) -> ScikitBuildSettings:
+        return self._settings
+
     def cmake(self) -> Generator[str, None, None]:
-        cmake_min = self._settings.cmake.minimum_version
+        cmake_min = self.settings.cmake.minimum_version
         cmake = best_program(
             get_cmake_programs(module=False), minimum_version=cmake_min
         )
@@ -73,7 +78,7 @@ def ninja(self) -> Generator[str, None, None]:
         if os.environ.get("CMAKE_MAKE_PROGRAM", ""):
             return
 
-        ninja_min = self._settings.ninja.minimum_version
+        ninja_min = self.settings.ninja.minimum_version
         ninja = best_program(
             get_ninja_programs(module=False), minimum_version=ninja_min
         )
@@ -82,7 +87,7 @@ def ninja(self) -> Generator[str, None, None]:
             return
 
         if (
-            self._settings.ninja.make_fallback
+            self.settings.ninja.make_fallback
             and not is_known_platform(known_wheels("ninja"))
             and list(get_make_programs())
         ):
@@ -93,7 +98,7 @@ def ninja(self) -> Generator[str, None, None]:
         yield f"ninja>={ninja_min}"
 
     def dynamic_metadata(self) -> Generator[str, None, None]:
-        for dynamic_metadata in self._settings.metadata.values():
+        for dynamic_metadata in self.settings.metadata.values():
             if "provider" in dynamic_metadata:
                 config = dynamic_metadata.copy()
                 provider = config.pop("provider")

src/scikit_build_core/resources/scikit-build.schema.json

@@ -110,6 +110,11 @@
           "type": "boolean",
           "default": true,
           "description": "If set to True, try to build a reproducible distribution (Unix and Python 3.9+ recommended).  ``SOURCE_DATE_EPOCH`` will be used for timestamps, or a fixed value if not set."
+        },
+        "cmake": {
+          "type": "boolean",
+          "default": false,
+          "description": "If set to True, CMake will be run before building the SDist."
         }
       }
     },
@@ -137,7 +142,7 @@
         "install-dir": {
           "type": "string",
           "default": "",
-          "description": "The install directory for the wheel. This is relative to the platlib root. EXPERIMENTAL: An absolute path will be one level higher than the platlib root, giving access to \"/platlib\", \"/data\", \"/headers\", and \"/scripts\"."
+          "description": "The install directory for the wheel. This is relative to the platlib root. You might set this to the package name. The original dir is still at SKBUILD_PLATLIB_DIR (also SKBUILD_DATA_DIR, etc. are available). EXPERIMENTAL: An absolute path will be one level higher than the platlib root, giving access to \"/platlib\", \"/data\", \"/headers\", and \"/scripts\"."
         },
         "license-files": {
           "type": "array",

src/scikit_build_core/settings/skbuild_model.py

@@ -113,6 +113,11 @@ class SDistSettings:
     fixed value if not set.
     """
 
+    cmake: bool = False
+    """
+    If set to True, CMake will be run before building the SDist.
+    """
+
 
 @dataclasses.dataclass
 class WheelSettings:
@@ -142,6 +147,8 @@ class WheelSettings:
     install_dir: str = ""
     """
     The install directory for the wheel. This is relative to the platlib root.
+    You might set this to the package name. The original dir is still at
+    SKBUILD_PLATLIB_DIR (also SKBUILD_DATA_DIR, etc. are available).
     EXPERIMENTAL: An absolute path will be one level higher than the platlib
     root, giving access to "/platlib", "/data", "/headers", and "/scripts".
     """

src/scikit_build_core/setuptools/build_meta.py

@@ -7,6 +7,8 @@
     prepare_metadata_for_build_wheel,
 )
 
+from ..builder.get_requires import GetRequires
+
 if hasattr(setuptools.build_meta, "build_editable"):
     from setuptools.build_meta import build_editable
 
@@ -38,14 +40,18 @@ def get_requires_for_build_sdist(
     setuptools_reqs = setuptools.build_meta.get_requires_for_build_sdist(
         config_settings
     )
-    return [*setuptools_reqs]
+    requires = GetRequires(config_settings)
+
+    # These are only injected if cmake is required for the SDist step
+    cmake_requires = (
+        [*requires.cmake(), *requires.ninja()] if requires.settings.sdist.cmake else []
+    )
+    return [*setuptools_reqs, *cmake_requires]
 
 
 def get_requires_for_build_wheel(
     config_settings: dict[str, str | list[str]] | None = None
 ) -> list[str]:
-    from ..builder.get_requires import GetRequires
-
     requires = GetRequires(config_settings)
 
     setuptools_reqs = setuptools.build_meta.get_requires_for_build_wheel(
@@ -60,8 +66,6 @@ def get_requires_for_build_wheel(
     def get_requires_for_build_editable(
         config_settings: dict[str, str | list[str]] | None = None
     ) -> list[str]:
-        from ..builder.get_requires import GetRequires
-
         requires = GetRequires(config_settings)
         setuptools_reqs = setuptools.build_meta.get_requires_for_build_editable(
             config_settings