feat: add support for free-threaded (no-gil) Python 3.13

bin/update_pythons.py

@@ -58,7 +58,7 @@ AnyConfig = Union[ConfigWinCP, ConfigWinPP, ConfigMacOS]
 
 
 class WindowsVersions:
-    def __init__(self, arch_str: ArchStr) -> None:
+    def __init__(self, arch_str: ArchStr, free_threaded: bool) -> None:
         response = requests.get("https://api.nuget.org/v3/index.json")
         response.raise_for_status()
         api_info = response.json()
@@ -72,7 +72,11 @@ class WindowsVersions:
 
         self.arch_str = arch_str
         self.arch = ARCH_DICT[arch_str]
+        self.free_threaded = free_threaded
+
         package = PACKAGE_DICT[arch_str]
+        if free_threaded:
+            package = f"{package}-freethreaded"
 
         response = requests.get(f"{endpoint}{package}/index.json")
         response.raise_for_status()
@@ -92,8 +96,9 @@ class WindowsVersions:
         if not versions:
             return None
 
+        flags = "t" if self.free_threaded else ""
         version = versions[0]
-        identifier = f"cp{version.major}{version.minor}-{self.arch}"
+        identifier = f"cp{version.major}{version.minor}{flags}-{self.arch}"
         return ConfigWinCP(
             identifier=identifier,
             version=self.version_dict[version],
@@ -233,9 +238,12 @@ class CPythonVersions:
 
 class AllVersions:
     def __init__(self) -> None:
-        self.windows_32 = WindowsVersions("32")
+        self.windows_32 = WindowsVersions("32", False)
-        self.windows_64 = WindowsVersions("64")
+        self.windows_t_32 = WindowsVersions("32", True)
-        self.windows_arm64 = WindowsVersions("ARM64")
+        self.windows_64 = WindowsVersions("64", False)
+        self.windows_t_64 = WindowsVersions("64", True)
+        self.windows_arm64 = WindowsVersions("ARM64", False)
+        self.windows_t_arm64 = WindowsVersions("ARM64", True)
         self.windows_pypy_64 = PyPyVersions("64")
 
         self.macos_cpython = CPythonVersions()
@@ -259,14 +267,19 @@ class AllVersions:
                     config_update = self.macos_pypy.update_version_macos(spec)
                 elif "macosx_arm64" in identifier:
                     config_update = self.macos_pypy_arm64.update_version_macos(spec)
-        elif "win32" in identifier:
+        elif "t-win32" in identifier and identifier.startswith("cp"):
-            if identifier.startswith("cp"):
+            config_update = self.windows_t_32.update_version_windows(spec)
-                config_update = self.windows_32.update_version_windows(spec)
+        elif "win32" in identifier and identifier.startswith("cp"):
+            config_update = self.windows_32.update_version_windows(spec)
+        elif "t-win_amd64" in identifier and identifier.startswith("cp"):
+            config_update = self.windows_t_64.update_version_windows(spec)
         elif "win_amd64" in identifier:
             if identifier.startswith("cp"):
                 config_update = self.windows_64.update_version_windows(spec)
             elif identifier.startswith("pp"):
                 config_update = self.windows_pypy_64.update_version_windows(spec)
+        elif "t-win_arm64" in identifier and identifier.startswith("cp"):
+            config_update = self.windows_t_arm64.update_version_windows(spec)
         elif "win_arm64" in identifier and identifier.startswith("cp"):
             config_update = self.windows_arm64.update_version_windows(spec)
 

cibuildwheel/linux.py

@@ -337,6 +337,10 @@ def build_in_container(
             virtualenv_env = env.copy()
             virtualenv_env["PATH"] = f"{venv_dir / 'bin'}:{virtualenv_env['PATH']}"
 
+            # TODO remove me once virtualenv provides pip>=24.1b1
+            if config.version == "3.13":
+                container.call(["pip", "install", "pip>=24.1b1"], env=virtualenv_env)
+
             if build_options.before_test:
                 before_test_prepared = prepare_command(
                     build_options.before_test,

cibuildwheel/macos.py

@@ -575,6 +575,10 @@ def build(options: Options, tmp_path: Path) -> None:
                     # check that we are using the Python from the virtual environment
                     call_with_arch("which", "python", env=virtualenv_env)
 
+                    # TODO remove me once virtualenv provides pip>=24.1b1
+                    if config.version == "3.13":
+                        call("python", "-m", "pip", "install", "pip>=24.1b1", env=virtualenv_env)
+
                     if build_options.before_test:
                         before_test_prepared = prepare_command(
                             build_options.before_test,

cibuildwheel/resources/build-platforms.toml

@@ -8,6 +8,7 @@ python_configurations = [
   { identifier = "cp311-manylinux_x86_64", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-manylinux_x86_64", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-manylinux_x86_64", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_x86_64", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "cp36-manylinux_i686", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
   { identifier = "cp37-manylinux_i686", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
   { identifier = "cp38-manylinux_i686", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -16,6 +17,7 @@ python_configurations = [
   { identifier = "cp311-manylinux_i686", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-manylinux_i686", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-manylinux_i686", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_i686", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "pp37-manylinux_x86_64", version = "3.7", path_str = "/opt/python/pp37-pypy37_pp73" },
   { identifier = "pp38-manylinux_x86_64", version = "3.8", path_str = "/opt/python/pp38-pypy38_pp73" },
   { identifier = "pp39-manylinux_x86_64", version = "3.9", path_str = "/opt/python/pp39-pypy39_pp73" },
@@ -28,6 +30,7 @@ python_configurations = [
   { identifier = "cp311-manylinux_aarch64", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-manylinux_aarch64", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-manylinux_aarch64", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_aarch64", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "cp36-manylinux_ppc64le", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
   { identifier = "cp37-manylinux_ppc64le", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
   { identifier = "cp38-manylinux_ppc64le", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -36,6 +39,7 @@ python_configurations = [
   { identifier = "cp311-manylinux_ppc64le", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-manylinux_ppc64le", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-manylinux_ppc64le", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_ppc64le", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "cp36-manylinux_s390x", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
   { identifier = "cp37-manylinux_s390x", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
   { identifier = "cp38-manylinux_s390x", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -44,6 +48,7 @@ python_configurations = [
   { identifier = "cp311-manylinux_s390x", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-manylinux_s390x", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-manylinux_s390x", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_s390x", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "pp37-manylinux_aarch64", version = "3.7", path_str = "/opt/python/pp37-pypy37_pp73" },
   { identifier = "pp38-manylinux_aarch64", version = "3.8", path_str = "/opt/python/pp38-pypy38_pp73" },
   { identifier = "pp39-manylinux_aarch64", version = "3.9", path_str = "/opt/python/pp39-pypy39_pp73" },
@@ -60,6 +65,7 @@ python_configurations = [
   { identifier = "cp311-musllinux_x86_64", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-musllinux_x86_64", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-musllinux_x86_64", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_x86_64", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "cp36-musllinux_i686", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
   { identifier = "cp37-musllinux_i686", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
   { identifier = "cp38-musllinux_i686", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -68,6 +74,7 @@ python_configurations = [
   { identifier = "cp311-musllinux_i686", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-musllinux_i686", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-musllinux_i686", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_i686", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "cp36-musllinux_aarch64", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
   { identifier = "cp37-musllinux_aarch64", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
   { identifier = "cp38-musllinux_aarch64", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -76,6 +83,7 @@ python_configurations = [
   { identifier = "cp311-musllinux_aarch64", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-musllinux_aarch64", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-musllinux_aarch64", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_aarch64", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "cp36-musllinux_ppc64le", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
   { identifier = "cp37-musllinux_ppc64le", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
   { identifier = "cp38-musllinux_ppc64le", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -84,6 +92,7 @@ python_configurations = [
   { identifier = "cp311-musllinux_ppc64le", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-musllinux_ppc64le", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-musllinux_ppc64le", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_ppc64le", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
   { identifier = "cp36-musllinux_s390x", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
   { identifier = "cp37-musllinux_s390x", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
   { identifier = "cp38-musllinux_s390x", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -92,6 +101,7 @@ python_configurations = [
   { identifier = "cp311-musllinux_s390x", version = "3.11", path_str = "/opt/python/cp311-cp311" },
   { identifier = "cp312-musllinux_s390x", version = "3.12", path_str = "/opt/python/cp312-cp312" },
   { identifier = "cp313-musllinux_s390x", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_s390x", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
 ]
 
 [macos]
@@ -142,12 +152,15 @@ python_configurations = [
   { identifier = "cp312-win32", version = "3.12.3", arch = "32" },
   { identifier = "cp312-win_amd64", version = "3.12.3", arch = "64" },
   { identifier = "cp313-win32", version = "3.13.0-b1", arch = "32" },
+  { identifier = "cp313t-win32", version = "3.13.0-b1", arch = "32" },
   { identifier = "cp313-win_amd64", version = "3.13.0-b1", arch = "64" },
+  { identifier = "cp313t-win_amd64", version = "3.13.0-b1", arch = "64" },
   { identifier = "cp39-win_arm64", version = "3.9.10", arch = "ARM64" },
   { identifier = "cp310-win_arm64", version = "3.10.11", arch = "ARM64" },
   { identifier = "cp311-win_arm64", version = "3.11.9", arch = "ARM64" },
   { identifier = "cp312-win_arm64", version = "3.12.3", arch = "ARM64" },
   { identifier = "cp313-win_arm64", version = "3.13.0-b1", arch = "ARM64" },
+  { identifier = "cp313t-win_arm64", version = "3.13.0-b1", arch = "ARM64" },
   { identifier = "pp37-win_amd64", version = "3.7", arch = "64", url = "https://downloads.python.org/pypy/pypy3.7-v7.3.9-win64.zip" },
   { identifier = "pp38-win_amd64", version = "3.8", arch = "64", url = "https://downloads.python.org/pypy/pypy3.8-v7.3.11-win64.zip" },
   { identifier = "pp39-win_amd64", version = "3.9", arch = "64", url = "https://downloads.python.org/pypy/pypy3.9-v7.3.16-win64.zip" },

cibuildwheel/resources/constraints-python313.txt

@@ -16,7 +16,7 @@ packaging==24.0
     # via
     #   build
     #   delocate
-pip==24.0
+pip==24.1b1
     # via -r cibuildwheel/resources/constraints.in
 platformdirs==4.2.2
     # via virtualenv

cibuildwheel/resources/constraints.in

@@ -1,4 +1,5 @@
-pip
+pip>=24.1b1 ; python_version >= '3.13'
+pip ; python_version < '3.13'
 build
 delocate
 virtualenv

cibuildwheel/util.py

@@ -238,13 +238,15 @@ class BuildSelector:
     requires_python: SpecifierSet | None = None
 
     # a pattern that skips prerelease versions, when include_prereleases is False.
-    PRERELEASE_SKIP: ClassVar[str] = "cp313-*"
+    PRERELEASE_SKIP: ClassVar[str] = "cp313-* cp313t-*"
     prerelease_pythons: bool = False
 
     def __call__(self, build_id: str) -> bool:
         # Filter build selectors by python_requires if set
         if self.requires_python is not None:
             py_ver_str = build_id.split("-")[0]
+            if py_ver_str.endswith("t"):
+                py_ver_str = py_ver_str[:-1]
             major = int(py_ver_str[2])
             minor = int(py_ver_str[3:])
             version = Version(f"{major}.{minor}.99")
@@ -645,10 +647,13 @@ def find_compatible_wheel(wheels: Sequence[T], identifier: str) -> T | None:
     """
 
     interpreter, platform = identifier.split("-")
+    free_threaded = interpreter.endswith("t")
+    if free_threaded:
+        interpreter = interpreter[:-1]
     for wheel in wheels:
         _, _, _, tags = parse_wheel_filename(wheel.name)
         for tag in tags:
-            if tag.abi == "abi3":
+            if tag.abi == "abi3" and not free_threaded:
                 # ABI3 wheels must start with cp3 for impl and tag
                 if not (interpreter.startswith("cp3") and tag.interpreter.startswith("cp3")):
                     continue

cibuildwheel/windows.py

@@ -44,7 +44,9 @@ from .util import (
 )
 
 
-def get_nuget_args(version: str, arch: str, output_directory: Path) -> list[str]:
+def get_nuget_args(
+    version: str, arch: str, free_threaded: bool, output_directory: Path
+) -> list[str]:
     package_name = {
         "32": "pythonx86",
         "64": "python",
@@ -53,6 +55,8 @@ def get_nuget_args(version: str, arch: str, output_directory: Path) -> list[str]
         "x86": "pythonx86",
         "AMD64": "python",
     }[arch]
+    if free_threaded:
+        package_name = f"{package_name}-freethreaded"
     return [
         package_name,
         "-Version",
@@ -106,11 +110,12 @@ def _ensure_nuget() -> Path:
     return nuget
 
 
-def install_cpython(version: str, arch: str) -> Path:
+def install_cpython(version: str, arch: str, free_threaded: bool) -> Path:
     base_output_dir = CIBW_CACHE_PATH / "nuget-cpython"
-    nuget_args = get_nuget_args(version, arch, base_output_dir)
+    nuget_args = get_nuget_args(version, arch, free_threaded, base_output_dir)
     installation_path = base_output_dir / (nuget_args[0] + "." + version) / "tools"
-    with FileLock(str(base_output_dir) + f"-{version}-{arch}.lock"):
+    free_threaded_str = "-freethreaded" if free_threaded else ""
+    with FileLock(str(base_output_dir) + f"-{version}{free_threaded_str}-{arch}.lock"):
         if not installation_path.exists():
             nuget = _ensure_nuget()
             call(nuget, "install", *nuget_args)
@@ -224,18 +229,21 @@ def setup_python(
     log.step(f"Installing Python {implementation_id}...")
     if implementation_id.startswith("cp"):
         native_arch = platform_module.machine()
+        free_threaded = implementation_id.endswith("t")
         if python_configuration.arch == "ARM64" != native_arch:
             # To cross-compile for ARM64, we need a native CPython to run the
             # build, and a copy of the ARM64 import libraries ('.\libs\*.lib')
             # for any extension modules.
             python_libs_base = install_cpython(
-                python_configuration.version, python_configuration.arch
+                python_configuration.version, python_configuration.arch, free_threaded
             )
             python_libs_base = python_libs_base.parent / "libs"
             log.step(f"Installing native Python {native_arch} for cross-compilation...")
-            base_python = install_cpython(python_configuration.version, native_arch)
+            base_python = install_cpython(python_configuration.version, native_arch, free_threaded)
         else:
-            base_python = install_cpython(python_configuration.version, python_configuration.arch)
+            base_python = install_cpython(
+                python_configuration.version, python_configuration.arch, free_threaded
+            )
     elif implementation_id.startswith("pp"):
         assert python_configuration.url is not None
         base_python = install_pypy(tmp, python_configuration.arch, python_configuration.url)
@@ -521,6 +529,10 @@ def build(options: Options, tmp_path: Path) -> None:
                 # check that we are using the Python from the virtual environment
                 call("where", "python", env=virtualenv_env)
 
+                # TODO remove me once virtualenv provides pip>=24.1b1
+                if config.version.startswith("3.13."):
+                    call("python", "-m", "pip", "install", "--pre", "-U", "pip", env=virtualenv_env)
+
                 if build_options.before_test:
                     before_test_prepared = prepare_command(
                         build_options.before_test,

test/test_abi_variants.py

@@ -13,9 +13,14 @@ build-backend = "setuptools.build_meta"
 limited_api_project = test_projects.new_c_project(
     setup_py_add=textwrap.dedent(
         r"""
+        import sysconfig
+
+        IS_CPYTHON = sys.implementation.name == "cpython"
+        Py_GIL_DISABLED = sysconfig.get_config_var("Py_GIL_DISABLED")
+        CAN_USE_ABI3 = IS_CPYTHON and not Py_GIL_DISABLED
         cmdclass = {}
         extension_kwargs = {}
-        if sys.version_info[:2] >= (3, 8):
+        if CAN_USE_ABI3 and sys.version_info[:2] >= (3, 8):
             from wheel.bdist_wheel import bdist_wheel as _bdist_wheel
 
             class bdist_wheel_abi3(_bdist_wheel):
@@ -47,7 +52,8 @@ def test_abi3(tmp_path):
     actual_wheels = utils.cibuildwheel_run(
         project_dir,
         add_env={
-            "CIBW_SKIP": "pp* ",  # PyPy does not have a Py_LIMITED_API equivalent
+            # free_threaded and PyPy do not have a Py_LIMITED_API equivalent, just build one of those
+            "CIBW_BUILD": "cp3?-* cp31?-* cp313t-* pp310-*"
         },
     )
 
@@ -55,7 +61,9 @@ def test_abi3(tmp_path):
     expected_wheels = [
         w.replace("cp38-cp38", "cp38-abi3")
         for w in utils.expected_wheels("spam", "0.1.0")
-        if "-pp" not in w and "-cp39" not in w and "-cp31" not in w
+        if ("-pp310" in w or "-pp" not in w)
+        and "-cp39" not in w
+        and ("-cp313t" in w or "-cp31" not in w)
     ]
     assert set(actual_wheels) == set(expected_wheels)
 
@@ -177,7 +185,7 @@ def test_abi_none(tmp_path, capfd):
             "CIBW_TEST_REQUIRES": "pytest",
             "CIBW_TEST_COMMAND": "pytest {project}/test",
             # limit the number of builds for test performance reasons
-            "CIBW_BUILD": "cp38-* cp310-* pp39-*",
+            "CIBW_BUILD": "cp38-* cp310-* cp313t-* pp310-*",
         },
     )
 

test/utils.py

@@ -176,6 +176,8 @@ def expected_wheels(
             "cp312-cp312",
             "cp313-cp313",
         ]
+        if platform != "macos":
+            python_abi_tags.append("cp313-cp313t")
 
         if machine_arch in ["x86_64", "AMD64", "x86", "aarch64"]:
             python_abi_tags += [