scikit-build · henryiii · Jul 16, 2026 · Jul 17, 2026 · Jul 17, 2026
diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
@@ -241,7 +241,7 @@ build-backend = "scikit_build_core.build"
 [project]
 name = "cmake_example"
 version = "0.0.1"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 
 [project.optional-dependencies]
 test = ["pytest>=6.0"]
@@ -275,7 +275,7 @@ setup(
     cmake_source_dir=".",
     zip_safe=False,
     extras_require={"test": ["pytest>=6.0"]},
-    python_requires=">=3.8",
+    python_requires=">=3.9",
 )
 ```
 

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -110,7 +110,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "pypy-3.11", "3.13", "3.14", "3.15"]
+        python-version: ["3.9", "pypy-3.11", "3.13", "3.14", "3.15"]
         runs-on: [ubuntu-latest]
         cmake-version: ["3.15.x"]
 
@@ -124,9 +124,6 @@ jobs:
           - python-version: "pypy-3.9"
             runs-on: ubuntu-latest
             cmake-version: "3.15.x"
-          - python-version: "3.8"
-            runs-on: ubuntu-latest
-            cmake-version: "3.21.x"
           - python-version: "3.9"
             runs-on: ubuntu-latest
             cmake-version: "3.20.x"
@@ -146,7 +143,7 @@ jobs:
           - python-version: "3.15t"
             runs-on: macos-latest
             cmake-version: "4.2.x"
-          - python-version: "3.8"
+          - python-version: "3.9"
             runs-on: macos-latest
             cmake-version: "3.21.x"
           - python-version: "3.9"
@@ -161,7 +158,7 @@ jobs:
           - python-version: "3.11"
             runs-on: ubuntu-latest
             cmake-version: "3.26.x"
-          - python-version: "3.8"
+          - python-version: "3.9"
             runs-on: windows-2022
             cmake-version: "3.24.x"
           # CMake < 4.2 cannot detect Visual Studio 2026, so rows testing older
@@ -181,7 +178,7 @@ jobs:
           - python-version: "3.14"
             runs-on: windows-2025-vs2026
             cmake-version: "4.2.x"
-          - python-version: "3.8"
+          - python-version: "3.9"
             runs-on: ubuntu-22.04
             cmake-version: "3.15.x"
           - python-version: "3.13"
@@ -276,7 +273,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.11"]
+        python-version: ["3.9", "3.11"]
         # TODO: investigate failure with macos-latest (#1167)
         # windows-2022: this job uses CMake 3.21, which cannot detect VS 2026;
         # windows-latest/windows-2025 are migrating to VS 2026 by default

diff --git a/README.md b/README.md
@@ -75,7 +75,7 @@ features over classic Scikit-build:
 Current requirements:
 
 - The minimum supported CMake is 3.15
-- The minimum supported Python is 3.8 (3.7+ for 0.10.x and older)
+- The minimum supported Python is 3.9 (3.8+ for 1.0.x and older)
 
 The recommended interface is the native pyproject builder. Other backends are
 also available:

diff --git a/docs/configuration/editable.md b/docs/configuration/editable.md
@@ -11,8 +11,7 @@ Recommendations:
 - You need to reinstall to pick up new files.
 
 Resources (via `importlib.resources`) are supported and tested on all supported
-Python versions. On Python 3.8, use the `importlib_resources` backport, since
-`importlib.resources.files` was added to the standard library in Python 3.9.
+Python versions.
 
 ```console
 # Very experimental rebuild on initial import feature

diff --git a/docs/configuration/index.md b/docs/configuration/index.md
@@ -415,12 +415,12 @@ support:
 
 ```toml
 [tool.scikit-build]
-wheel.py-api = "cp38"
+wheel.py-api = "cp39"
 ```
 
 | `wheel.py-api`   | Use for                                           | Resulting tags     |
 | ---------------- | ------------------------------------------------- | ------------------ |
-| `"cp38"`         | Limited API / Stable ABI extension (CPython 3.8+) | `cp38-abi3`        |
+| `"cp39"`         | Limited API / Stable ABI extension (CPython 3.9+) | `cp39-abi3`        |
 | `"py3"`          | Extension not using the Python API                | `py3-none`         |
 | `"py2.py3"`      | Same, but installable on Python 2 as well         | `py2.py3-none`     |
 | `"cp315t"`       | Free-threaded stable ABI ([PEP 803][])            | `cp315-abi3t`      |

diff --git a/docs/examples/downstream/nanobind_example/CMakeLists.txt b/docs/examples/downstream/nanobind_example/CMakeLists.txt
@@ -29,7 +29,7 @@ endif()
 
 # Try to import all Python components potentially needed by nanobind
 find_package(
-  Python 3.8 REQUIRED
+  Python 3.9 REQUIRED
   COMPONENTS Interpreter Development.Module
   OPTIONAL_COMPONENTS Development.SABIModule)
 

diff --git a/docs/examples/downstream/nanobind_example/pyproject.toml b/docs/examples/downstream/nanobind_example/pyproject.toml
@@ -7,7 +7,7 @@ name = "nanobind-example"
 version = "0.0.1"
 description = "An example minimal project that compiles bindings using nanobind and scikit-build"
 readme = "README.md"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 authors = [
     { name = "Wenzel Jakob", email = "wenzel.jakob@epfl.ch" },
 ]

diff --git a/docs/examples/downstream/pybind11_example/README.md b/docs/examples/downstream/pybind11_example/README.md
@@ -8,7 +8,7 @@
 | pip builds   | [![Pip Actions Status][actions-pip-badge]][actions-pip-link]       |
 
 An example project built with [pybind11](https://github.com/pybind/pybind11) and
-scikit-build-core. Python 3.8+ (see older commits for older versions of Python).
+scikit-build-core. Python 3.9+ (see older commits for older versions of Python).
 
 [gitter-badge]: https://badges.gitter.im/pybind/Lobby.svg
 [gitter-link]: https://gitter.im/pybind/Lobby

diff --git a/docs/examples/downstream/pybind11_example/pyproject.toml b/docs/examples/downstream/pybind11_example/pyproject.toml
@@ -11,12 +11,11 @@ readme = "README.md"
 authors = [
   { name = "My Name", email = "me@email.com" },
 ]
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 classifiers = [
   "Development Status :: 4 - Beta",
   "License :: OSI Approved :: MIT License",
   "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",

diff --git a/docs/guide/cmakelists.md b/docs/guide/cmakelists.md
@@ -134,7 +134,7 @@ in your `pyproject.toml`:
 
 ```toml
 [tool.scikit-build]
-wheel.py-api = "cp38"
+wheel.py-api = "cp39"
 ```
 
 The possible values and the resulting wheel tags are covered in

diff --git a/docs/reference/configs.md b/docs/reference/configs.md
@@ -1013,7 +1013,7 @@ print(mk_skbuild_docs())
 
   The default (empty string) will use the default Python version.
 
-  You can also set this to "cp38" to enable the CPython 3.8+ Stable
+  You can also set this to "cp39" to enable the CPython 3.9+ Stable
   ABI / Limited API (only on CPython and if the version is sufficient,
   otherwise this has no effect). For free-threaded Python, you can use
   "cp315t" to enable the free-threaded stable ABI (only on CPython

diff --git a/pyproject.toml b/pyproject.toml
@@ -9,7 +9,7 @@ authors = [
 ]
 description = "Build backend for CMake based projects"
 readme = "README.md"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 license = "Apache-2.0"
 classifiers = [
     "Topic :: Scientific/Engineering",
@@ -20,7 +20,6 @@ classifiers = [
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
     "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",
@@ -37,7 +36,6 @@ dynamic = ["version"]
 
 dependencies = [
     "exceptiongroup >=1.0; python_version<'3.11'",
-    "importlib-resources >=1.3; python_version<'3.9'",
     "packaging >=23.2",
     "pathspec >=0.12.0",
     "tomli >=1.2.2; python_version<'3.11'",
@@ -52,10 +50,9 @@ wheels = [
     "ninja; sys_platform!='win32'",
 ]
 wheel-free-setuptools = [
-    'setuptools>=70.1; python_version>="3.8"',
+    'setuptools>=70.1',
 ]
 setuptools = [
-    'setuptools >=43; python_version<"3.9"',
     'setuptools >=45; python_version=="3.9"',
     'setuptools >=49; python_version>="3.10" and python_version<"3.12"',
     'setuptools >=66.1; python_version>="3.12"',
@@ -109,7 +106,6 @@ test-core = [
     "pip>=24.1; python_version>='3.13'",
     "pytest >=7.2,!=9.1.0",  # 9.1.0 regression overriding params-fixtures: pytest-dev/pytest#13974
     "pytest-subprocess >=1.5",
-    'setuptools >=43; python_version<"3.9"',
     'setuptools >=45; python_version=="3.9"',
     'setuptools >=49; python_version>="3.10" and python_version<"3.12"',
     'setuptools >=66.1; python_version>="3.12"',
@@ -129,7 +125,6 @@ test-meta = [
 test-numpy = [
     { include-group = "test-core" },
     "numpy>=1.24.1; python_version<'3.15' and platform_python_implementation!='PyPy' and (platform_system != 'Windows' or platform_machine != 'ARM64')",
-    "numpy~=1.24.1; python_version=='3.8' and platform_python_implementation=='PyPy'",
     "numpy~=2.0; python_version=='3.9' and platform_python_implementation=='PyPy'",
     "numpy~=2.2; python_version=='3.10' and platform_python_implementation=='PyPy'",
     "numpy~=2.4.1; python_version=='3.11' and platform_python_implementation=='PyPy'",
@@ -266,7 +261,7 @@ ignore_missing_imports = true
 
 
 [tool.pylint]
-py-version = "3.8"
+py-version = "3.9"
 jobs = "0"
 reports.output-format = "colorized"
 good-names = ["f"]
@@ -364,8 +359,6 @@ docstring-code-format = true
 "tomllib".msg = "Use scikit_build_core._compat.tomllib instead."
 "importlib_metadata".msg = "Use importlib.metadata directly instead."
 "importlib.metadata.entry_points".msg = "Use scikit_build_core._compat.importlib.metadata.entry_points instead."
-"importlib.resources".msg = "Use scikit_build_core._compat.importlib.resources instead."
-"importlib_resources".msg = "Use scikit_build_core._compat.importlib.resources instead."
 "pyproject_metadata".msg = "Use scikit_build_core._vendor.pyproject_metadata instead."
 "setuptools.errors".msg = "Use scikit_build_core._compat.setuptools.errors instead."
 

diff --git a/src/scikit_build_core/_compat/importlib/metadata.py b/src/scikit_build_core/_compat/importlib/metadata.py
@@ -1,18 +1,15 @@
 from __future__ import annotations
 
-__lazy_modules__ = {"typing"}
-
 import importlib.metadata
 import sys
-import typing
 
 TYPE_CHECKING = False
 
 if TYPE_CHECKING:
     if sys.version_info < (3, 10):
         from importlib.metadata import EntryPoint
 
-        EntryPoints = typing.List[EntryPoint]
+        EntryPoints = list[EntryPoint]
     else:
         from importlib.metadata import EntryPoints
 

diff --git a/src/scikit_build_core/_compat/importlib/resources.py b/src/scikit_build_core/_compat/importlib/resources.py
diff --git a/src/scikit_build_core/_compat/typing.py b/src/scikit_build_core/_compat/typing.py
@@ -7,11 +7,6 @@
 
 TYPE_CHECKING = False
 
-if sys.version_info < (3, 9):
-    from typing_extensions import Annotated, get_args, get_origin
-else:
-    from typing import Annotated, get_args, get_origin
-
 if sys.version_info < (3, 11):
     if TYPE_CHECKING:
         from typing_extensions import Self, assert_never
@@ -40,12 +35,9 @@ def TypeVar(  # noqa: N802
 
 
 __all__ = [
-    "Annotated",
     "Self",
     "TypeVar",
     "assert_never",
-    "get_args",
-    "get_origin",
 ]
 
 

diff --git a/src/scikit_build_core/_logging.py b/src/scikit_build_core/_logging.py
@@ -342,7 +342,7 @@ def rich_print(
     print(*args_2, flush=True, sep=sep, end=end, file=file)  # type: ignore[call-overload]
 
 
-@functools.lru_cache(maxsize=None)
+@functools.cache
 def rich_warning(
     *args: str,
     color: Literal[

diff --git a/src/scikit_build_core/build/_file_processor.py b/src/scikit_build_core/build/_file_processor.py
@@ -56,7 +56,7 @@ def symlink_escapes(path: Path) -> bool:
     stays consistent link by link (the last link is the one that gets
     resolved).
     """
-    target = os.readlink(path)
+    target = os.readlink(path)  # noqa: PTH115
     if os.path.isabs(target) or os.path.splitdrive(target)[0]:  # noqa: PTH117
         return True
     joined = os.path.normpath(os.path.join(os.path.dirname(path), target))  # noqa: PTH118, PTH120

diff --git a/src/scikit_build_core/build/metadata.py b/src/scikit_build_core/build/metadata.py
@@ -153,7 +153,7 @@ def get_standard_metadata(
             )
         except ImportError:
             logger.warning(
-                "Packaging 24.2+ required for license normalization. Please update (Python 3.8+ required)"
+                "Packaging 24.2+ required for license normalization. Please update"
             )
 
     # For scikit-build-core >= 0.11, we set METADATA 2.2 as minimum

diff --git a/src/scikit_build_core/builder/builder.py b/src/scikit_build_core/builder/builder.py
@@ -8,6 +8,8 @@
     f"{(__spec__.parent or '').rsplit('.', 1)[0]}.resources",
     f"{__spec__.parent}.generator",
     f"{__spec__.parent}.sysconfig",
+    "importlib",
+    "importlib.resources",
     "platform",
     "re",
     "shlex",
@@ -23,11 +25,12 @@
 import shlex
 import sys
 import sysconfig
+from importlib.resources import files
 from pathlib import Path
 from typing import Any
 
 from .. import __version__
-from .._compat.importlib import metadata, resources
+from .._compat.importlib import metadata
 from .._logging import logger
 from .._reproducible import get_reproducible_epoch
 from ..program_search import _macos_binary_is_x86
@@ -248,7 +251,7 @@ def _get_entry_point_search_path(self, entry_point: str) -> dict[str, list[Path]
                 "Loading search paths {} from entry-points: {}", entry_point, len(eps)
             )
             for ep in eps:
-                ep_value = _sanitize_path(resources.files(ep.load()))
+                ep_value = _sanitize_path(files(ep.load()))
                 logger.debug("{}: {} -> {}", ep.name, ep.value, ep_value)
                 if ep_value:
                     search_paths[ep.name] = ep_value