pypa · mayeut · Dec 6, 2025
diff --git a/.cirrus.yml b/.cirrus.yml
@@ -73,19 +73,3 @@ macos_arm64_task:
     - brew install python@3.12
     - python3.12 -m venv ${VENV_ROOT}
   <<: *RUN_TESTS
-
-macos_arm64_cp38_task:
-  macos_instance:
-    image: ghcr.io/cirruslabs/macos-runner:sequoia
-  env:
-    VENV_ROOT: ${HOME}/venv-cibuildwheel
-    PATH: ${VENV_ROOT}/bin:${PATH}
-    PYTEST_ADDOPTS: --run-cp38-universal2 -k 'test_cp38_arm64_testing_universal2_installer or test_arch_auto or test_dummy_serial'
-  install_pre_requirements_script:
-    - brew install python@3.12
-    - python3.12 -m venv ${VENV_ROOT}
-    - curl -fsSLO https://www.python.org/ftp/python/3.8.10/python-3.8.10-macos11.pkg
-    - sudo installer -pkg python-3.8.10-macos11.pkg -target /
-    - rm python-3.8.10-macos11.pkg
-    - sh "/Applications/Python 3.8/Install Certificates.command"
-  <<: *RUN_TESTS
diff --git a/README.md b/README.md
@@ -24,14 +24,12 @@ While cibuildwheel itself requires a recent Python version to run (we support th
 
 |                    | macOS Intel | macOS Apple Silicon | Windows 64bit | Windows 32bit | Windows Arm64 | manylinux<br/>musllinux x86_64 | manylinux<br/>musllinux i686 | manylinux<br/>musllinux aarch64 | manylinux<br/>musllinux ppc64le | manylinux<br/>musllinux s390x | manylinux<br/>musllinux armv7l | Android | iOS | Pyodide |
 |--------------------|----|-----|----|-----|-----|----|-----|----|-----|-----|---|-----|-----|-----|
-| CPython 3.8        | ✅ | ✅  | ✅  | ✅  | N/A | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | N/A |
 | CPython 3.9        | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅ | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | N/A |
 | CPython 3.10       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | N/A |
 | CPython 3.11       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | N/A |
 | CPython 3.12       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | ✅⁴ |
 | CPython 3.13³      | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | ✅  | ✅  | ✅⁴ |
 | CPython 3.14       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | ✅  | ✅  | N/A |
-| PyPy 3.8 v7.3      | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |
 | PyPy 3.9 v7.3      | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |
 | PyPy 3.10 v7.3     | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |
 | PyPy 3.11 v7.3     | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |

diff --git a/cibuildwheel/__main__.py b/cibuildwheel/__main__.py
@@ -534,10 +534,13 @@ def check_for_invalid_selectors(
                 msg += "This selector matches a group that wasn't enabled. Enable it using the `enable` option or remove this selector. "
 
             if "p2" in selector_ or "p35" in selector_:
-                msg += f"cibuildwheel 3.x no longer supports Python < 3.8. Please use the 1.x series or update `{selector_name}`. "
+                msg += f"cibuildwheel 4.x no longer supports Python < 3.9. Please use the 1.x series or update `{selector_name}`. "
                 error_type = errors.DeprecationError
             if "p36" in selector_ or "p37" in selector_:
-                msg += f"cibuildwheel 3.x no longer supports Python < 3.8. Please use the 2.x series or update `{selector_name}`. "
+                msg += f"cibuildwheel 4.x no longer supports Python < 3.9. Please use the 2.x series or update `{selector_name}`. "
+                error_type = errors.DeprecationError
+            if "p38" in selector_:
+                msg += f"cibuildwheel 4.x no longer supports Python < 3.9. Please use the 3.x series or update `{selector_name}`. "
                 error_type = errors.DeprecationError
 
             if selector_name == "build":

diff --git a/cibuildwheel/frontend.py b/cibuildwheel/frontend.py
@@ -4,7 +4,6 @@
 from collections.abc import Sequence
 from typing import Literal, Self, get_args
 
-from .logger import log
 from .util.helpers import parse_key_value_string
 
 BuildFrontendName = Literal["pip", "build", "build[uv]", "uv"]
@@ -36,12 +35,8 @@ def options_summary(self) -> str | dict[str, str]:
             return {"name": self.name, "args": repr(self.args)}
 
 
-def _get_verbosity_flags(level: int, frontend: BuildFrontendName, *, py38: bool) -> list[str]:
+def _get_verbosity_flags(level: int, frontend: BuildFrontendName) -> list[str]:
     if level < 0:
-        if frontend.startswith("build") and py38:
-            msg = f"build_verbosity {level} is not supported for {frontend} frontend. Ignoring."
-            log.warning(msg)
-            return []
         return ["-" + -level * "q"]
 
     if level > 0:
@@ -75,10 +70,10 @@ def parse_config_settings(config_settings_str: str) -> dict[str, str | list[str]
 
 
 def get_build_frontend_extra_flags(
-    build_frontend: BuildFrontendConfig, verbosity_level: int, config_settings: str, *, py38: bool
+    build_frontend: BuildFrontendConfig, verbosity_level: int, config_settings: str
 ) -> list[str]:
     return [
         *_split_config_settings(config_settings),
         *build_frontend.args,
-        *_get_verbosity_flags(verbosity_level, build_frontend.name, py38=py38),
+        *_get_verbosity_flags(verbosity_level, build_frontend.name),
     ]
@@ -457,7 +457,6 @@ def build_wheel(state: BuildState) -> Path:
                     state.options.build_frontend,
                     state.options.build_verbosity,
                     state.options.config_settings,
-                    py38=False,
                 ),
                 env=state.android_env,
             )
@@ -475,7 +474,6 @@ def build_wheel(state: BuildState) -> Path:
                     state.options.build_frontend,
                     state.options.build_verbosity,
                     state.options.config_settings,
-                    py38=False,
                 ),
                 env=state.android_env,
             )

@@ -490,7 +490,6 @@ def build(options: Options, tmp_path: Path) -> None:
                     build_frontend,
                     build_options.build_verbosity,
                     build_options.config_settings,
-                    py38=False,
                 )
 
                 match build_frontend.name:

diff --git a/cibuildwheel/platforms/linux.py b/cibuildwheel/platforms/linux.py
@@ -277,7 +277,6 @@ def build_in_container(
                 build_frontend,
                 build_options.build_verbosity,
                 build_options.config_settings,
-                py38=config.identifier[1:].startswith("p38"),
             )
 
             match build_frontend.name:

diff --git a/cibuildwheel/platforms/macos.py b/cibuildwheel/platforms/macos.py
@@ -475,7 +475,6 @@ def build(options: Options, tmp_path: Path) -> None:
                     build_frontend,
                     build_options.build_verbosity,
                     build_options.config_settings,
-                    py38=config.identifier[1:].startswith("p38"),
                 )
 
                 build_env = env.copy()
@@ -568,13 +567,6 @@ def build(options: Options, tmp_path: Path) -> None:
 
             if build_options.test_command and build_options.test_selector(config.identifier):
                 machine_arch = platform.machine()
-                python_arch = call(
-                    "python",
-                    "-sSc",
-                    "import platform; print(platform.machine())",
-                    env=env,
-                    capture_stdout=True,
-                ).strip()
                 testing_archs: list[Literal["x86_64", "arm64"]]
 
                 if config_is_arm64:
@@ -622,24 +614,6 @@ def build(options: Options, tmp_path: Path) -> None:
                         # skip this test
                         continue
 
-                    is_cp38 = config.identifier.startswith("cp38-")
-                    if testing_arch == "arm64" and is_cp38 and python_arch != "arm64":
-                        log.warning(
-                            unwrap(
-                                """
-                                While cibuildwheel can build CPython 3.8 universal2/arm64 wheels, we
-                                cannot test the arm64 part of them, even when running on an Apple
-                                Silicon machine. This is because we use the x86_64 installer of
-                                CPython 3.8. See the discussion in
-                                https://github.com/pypa/cibuildwheel/pull/1169 for the details. To
-                                silence this warning, set `CIBW_TEST_SKIP: "cp38-macosx_*:arm64"`.
-                                """
-                            )
-                        )
-
-                        # skip this test
-                        continue
-
                     log.step(
                         "Testing wheel..."
                         if testing_arch == machine_arch
@@ -696,33 +670,16 @@ def build(options: Options, tmp_path: Path) -> None:
                         shell_with_arch(before_test_prepared, env=virtualenv_env)
 
                     # install the wheel
-                    if is_cp38 and python_arch == "x86_64":
-                        virtualenv_env_install_wheel = virtualenv_env.copy()
-                        virtualenv_env_install_wheel["SYSTEM_VERSION_COMPAT"] = "0"
-                        log.notice(
-                            unwrap(
-                                """
-                                Setting SYSTEM_VERSION_COMPAT=0 to ensure CPython 3.8 can get
-                                correct macOS version and allow installation of wheels with
-                                MACOSX_DEPLOYMENT_TARGET >= 11.0.
-                                See https://github.com/pypa/cibuildwheel/issues/1767 for the
-                                details.
-                                """
-                            )
-                        )
-                    else:
-                        virtualenv_env_install_wheel = virtualenv_env
-
                     pip_install(
                         f"{repaired_wheel}{build_options.test_extras}",
-                        env=virtualenv_env_install_wheel,
+                        env=virtualenv_env,
                     )
 
                     # test the wheel
                     if build_options.test_requires:
                         pip_install(
                             *build_options.test_requires,
-                            env=virtualenv_env_install_wheel,
+                            env=virtualenv_env,
                         )
 
                     # run the tests from a temp dir, with an absolute path in the command

@@ -419,7 +419,6 @@ def build(options: Options, tmp_path: Path) -> None:
                     build_frontend,
                     build_options.build_verbosity,
                     build_options.config_settings,
-                    py38=False,
                 )
 
                 call(

diff --git a/cibuildwheel/platforms/windows.py b/cibuildwheel/platforms/windows.py
@@ -232,11 +232,6 @@ def setup_rust_cross_compile(
         )
 
 
-def can_use_uv(python_configuration: PythonConfiguration) -> bool:
-    conditions = (not python_configuration.identifier.startswith("pp38-"),)
-    return all(conditions)
-
-
 def setup_python(
     tmp: Path,
     python_configuration: PythonConfiguration,
@@ -268,9 +263,6 @@ def setup_python(
         raise ValueError(msg)
     assert base_python.exists()
 
-    if build_frontend == "build[uv]" and not can_use_uv(python_configuration):
-        build_frontend = "build"
-
     use_uv = build_frontend in {"build[uv]", "uv"}
     uv_path = find_uv()
 
@@ -405,7 +397,7 @@ def build(options: Options, tmp_path: Path) -> None:
         for config in python_configurations:
             build_options = options.build_options(config.identifier)
             build_frontend = build_options.build_frontend
-            use_uv = build_frontend.name in {"build[uv]", "uv"} and can_use_uv(config)
+            use_uv = build_frontend.name in {"build[uv]", "uv"}
             log.build_start(config.identifier)
 
             identifier_tmp_dir = tmp_path / config.identifier
@@ -453,7 +445,6 @@ def build(options: Options, tmp_path: Path) -> None:
                     build_frontend,
                     build_options.build_verbosity,
                     build_options.config_settings,
-                    py38=config.identifier[1:].startswith("p38"),
                 )
 
                 if (