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

bin/generate_schema.py

@@ -104,6 +104,10 @@
     description: Set environment variables on the host to pass-through to the container
       during the build.
     type: string_array
+  free-threaded-support:
+    type: boolean
+    default: false
+    description: The project supports free-threaded builds of Python (PEP703)
   manylinux-aarch64-image:
     type: string
     description: Specify alternative manylinux / musllinux container images
@@ -248,6 +252,7 @@
 del non_global_options["build"]
 del non_global_options["skip"]
 del non_global_options["test-skip"]
+del non_global_options["free-threaded-support"]
 
 overrides["items"]["properties"]["select"]["oneOf"] = string_array
 overrides["items"]["properties"] |= non_global_options.copy()

bin/update_pythons.py

@@ -58,7 +58,7 @@ class ConfigMacOS(TypedDict):
 
 
 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 @@ def __init__(self, arch_str: ArchStr) -> None:
 
         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 @@ def update_version_windows(self, spec: Specifier) -> ConfigWinCP | None:
         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 @@ def update_version_macos(
 
 class AllVersions:
     def __init__(self) -> None:
-        self.windows_32 = WindowsVersions("32")
-        self.windows_64 = WindowsVersions("64")
-        self.windows_arm64 = WindowsVersions("ARM64")
+        self.windows_32 = WindowsVersions("32", False)
+        self.windows_t_32 = WindowsVersions("32", True)
+        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 @@ def update_config(self, config: MutableMapping[str, str]) -> None:
                     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:
-            if identifier.startswith("cp"):
-                config_update = self.windows_32.update_version_windows(spec)
+        elif "t-win32" in identifier and identifier.startswith("cp"):
+            config_update = self.windows_t_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/options.py

@@ -117,7 +117,7 @@ def architectures(self) -> set[Architecture]:
         return self.globals.architectures
 
 
-Setting = Union[Mapping[str, str], Sequence[str], str, int]
+Setting = Union[Mapping[str, str], Sequence[str], str, int, bool]
 
 
 @dataclasses.dataclass(frozen=True)
@@ -196,7 +196,7 @@ def _resolve_cascade(
         if value is None:
             continue
 
-        if ignore_empty and not value:
+        if ignore_empty and not value and value is not False:
             continue
 
         value_string = _stringify_setting(value, list_sep, table_format)
@@ -258,7 +258,7 @@ def _stringify_setting(
             raise ConfigOptionError(msg)
         return list_sep.join(setting)
 
-    if isinstance(setting, int):
+    if isinstance(setting, (bool, int)):
         return str(setting)
 
     return setting
@@ -516,6 +516,10 @@ def globals(self) -> GlobalOptions:
         skip_config = self.reader.get("skip", env_plat=False, list_sep=" ")
         test_skip = self.reader.get("test-skip", env_plat=False, list_sep=" ")
 
+        free_threaded_support = strtobool(
+            self.reader.get("free-threaded-support", env_plat=False, ignore_empty=True)
+        )
+
         prerelease_pythons = args.prerelease_pythons or strtobool(
             self.env.get("CIBW_PRERELEASE_PYTHONS", "0")
         )
@@ -536,12 +540,14 @@ def globals(self) -> GlobalOptions:
             skip_config = ""
             architectures = Architecture.all_archs(self.platform)
             prerelease_pythons = True
+            free_threaded_support = True
 
         build_selector = BuildSelector(
             build_config=build_config,
             skip_config=skip_config,
             requires_python=requires_python,
             prerelease_pythons=prerelease_pythons,
+            free_threaded_support=free_threaded_support,
         )
         test_selector = TestSelector(skip_config=test_skip)
 

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/cibuildwheel.schema.json

@@ -255,6 +255,12 @@
       ],
       "title": "CIBW_ENVIRONMENT_PASS"
     },
+    "free-threaded-support": {
+      "type": "boolean",
+      "default": false,
+      "description": "The project supports free-threaded builds of Python (PEP703)",
+      "title": "CIBW_FREE_THREADED_SUPPORT"
+    },
     "manylinux-aarch64-image": {
       "type": "string",
       "description": "Specify alternative manylinux / musllinux container images",

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/resources/defaults.toml

@@ -2,6 +2,7 @@
 build = "*"
 skip = ""
 test-skip = ""
+free-threaded-support = false
 
 archs = ["auto"]
 build-frontend = "default"

cibuildwheel/util.py

@@ -238,13 +238,17 @@ 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
 
+    free_threaded_support: 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")
@@ -255,6 +259,10 @@ def __call__(self, build_id: str) -> bool:
         if not self.prerelease_pythons and selector_matches(self.PRERELEASE_SKIP, build_id):
             return False
 
+        # filter out free threaded pythons if self.free_threaded_support is False
+        if not self.free_threaded_support and selector_matches("*t-*", build_id):
+            return False
+
         should_build = selector_matches(self.build_config, build_id)
         should_skip = selector_matches(self.skip_config, build_id)
 
@@ -266,6 +274,7 @@ def options_summary(self) -> Any:
             "skip_config": self.skip_config,
             "requires_python": str(self.requires_python),
             "prerelease_pythons": self.prerelease_pythons,
+            "free_threaded_support": self.free_threaded_support,
         }
 
 
@@ -645,10 +654,13 @@ 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