feat: support building universal2/arm64 from x64_86 Python 3.8 (pypa#704)

Author: henryiii

README.md

@@ -28,7 +28,7 @@ What does it do?
 | CPython 3.5     | ✅ |   | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
 | CPython 3.6     | ✅ |   | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
 | CPython 3.7     | ✅ |   | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
-| CPython 3.8     | ✅ |   | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
+| CPython 3.8     | ✅ | ✅ | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
 | CPython 3.9     | ✅ | ✅ | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
 | PyPy 2.7 v7.3.3 | ✅ |    |    | ✅  | ✅ |    |    |    |   |
 | PyPy 3.6 v7.3.3 | ✅ |    |    | ✅  | ✅ |    |    |    |   |
@@ -48,7 +48,7 @@ Usage
 
 |                 | Linux | macOS | Windows | Linux ARM |
 |-----------------|-------|-------|---------|--------------|
-| GitHub Actions  | ✅    | ✅    | ✅      | ✅¹           |
+| GitHub Actions  | ✅    | ✅    | ✅      | ✅¹          |
 | Azure Pipelines | ✅    | ✅    | ✅      |              |
 | Travis CI       | ✅    | ✅    | ✅      | ✅           |
 | AppVeyor        | ✅    | ✅    | ✅      |              |

cibuildwheel/macos.py

@@ -293,22 +293,20 @@ def setup_python(
         # https://github.com/python/cpython/blob/a5ed2fe0eedefa1649aa93ee74a0bafc8e628a10/Lib/_osx_support.py#L260
         env.setdefault("ARCHFLAGS", "-arch x86_64")
 
-    if python_configuration.version == "3.9":
-        if python_configuration.identifier.endswith("x86_64"):
-            # even on the macos11.0 Python installer, on the x86_64 side it's
-            # compatible back to 10.9.
-            env.setdefault("_PYTHON_HOST_PLATFORM", "macosx-10.9-x86_64")
-            env.setdefault("ARCHFLAGS", "-arch x86_64")
-        elif config_is_arm64:
+    elif python_configuration.version not in {"3.6", "3.7"}:
+        if config_is_arm64:
             # macOS 11 is the first OS with arm64 support, so the wheels
             # have that as a minimum.
             env.setdefault("_PYTHON_HOST_PLATFORM", "macosx-11.0-arm64")
             env.setdefault("ARCHFLAGS", "-arch arm64")
         elif config_is_universal2:
-            if get_macos_version() < (10, 16):
-                # we can do universal2 builds on macos 10.15, but we need to
-                # set ARCHFLAGS otherwise CPython sets it to `-arch x86_64`
-                env.setdefault("ARCHFLAGS", "-arch arm64 -arch x86_64")
+            env.setdefault("_PYTHON_HOST_PLATFORM", "macosx-10.9-universal2")
+            env.setdefault("ARCHFLAGS", "-arch arm64 -arch x86_64")
+        elif python_configuration.identifier.endswith("x86_64"):
+            # even on the macos11.0 Python installer, on the x86_64 side it's
+            # compatible back to 10.9.
+            env.setdefault("_PYTHON_HOST_PLATFORM", "macosx-10.9-x86_64")
+            env.setdefault("ARCHFLAGS", "-arch x86_64")
 
     building_arm64 = config_is_arm64 or config_is_universal2
     if building_arm64 and get_macos_version() < (10, 16) and "SDKROOT" not in env:

cibuildwheel/resources/build-platforms.toml

@@ -40,10 +40,12 @@ python_configurations = [
   { identifier = "cp35-macosx_x86_64", version = "3.5", url = "https://www.python.org/ftp/python/3.5.4/python-3.5.4-macosx10.6.pkg" },
   { identifier = "cp36-macosx_x86_64", version = "3.6", url = "https://www.python.org/ftp/python/3.6.8/python-3.6.8-macosx10.9.pkg" },
   { identifier = "cp37-macosx_x86_64", version = "3.7", url = "https://www.python.org/ftp/python/3.7.9/python-3.7.9-macosx10.9.pkg" },
-  { identifier = "cp38-macosx_x86_64", version = "3.8", url = "https://www.python.org/ftp/python/3.8.9/python-3.8.9-macosx10.9.pkg" },
-  { identifier = "cp39-macosx_x86_64", version = "3.9", url = "https://www.python.org/ftp/python/3.9.4/python-3.9.4-macos11.pkg" },
-  { identifier = "cp39-macosx_arm64", version = "3.9", url = "https://www.python.org/ftp/python/3.9.4/python-3.9.4-macos11.pkg" },
-  { identifier = "cp39-macosx_universal2", version = "3.9", url = "https://www.python.org/ftp/python/3.9.4/python-3.9.4-macos11.pkg" },
+  { identifier = "cp38-macosx_x86_64", version = "3.8", url = "https://www.python.org/ftp/python/3.8.10/python-3.8.10-macosx10.9.pkg" },
+  { identifier = "cp38-macosx_arm64", version = "3.8", url = "https://www.python.org/ftp/python/3.8.10/python-3.8.10-macosx10.9.pkg" },
+  { identifier = "cp38-macosx_universal2", version = "3.8", url = "https://www.python.org/ftp/python/3.8.10/python-3.8.10-macosx10.9.pkg" },
+  { identifier = "cp39-macosx_x86_64", version = "3.9", url = "https://www.python.org/ftp/python/3.9.5/python-3.9.5-macos11.pkg" },
+  { identifier = "cp39-macosx_arm64", version = "3.9", url = "https://www.python.org/ftp/python/3.9.5/python-3.9.5-macos11.pkg" },
+  { identifier = "cp39-macosx_universal2", version = "3.9", url = "https://www.python.org/ftp/python/3.9.5/python-3.9.5-macos11.pkg" },
   { identifier = "pp27-macosx_x86_64", version = "2.7", url = "https://downloads.python.org/pypy/pypy2.7-v7.3.3-osx64.tar.bz2" },
   { identifier = "pp36-macosx_x86_64", version = "3.6", url = "https://downloads.python.org/pypy/pypy3.6-v7.3.3-osx64.tar.bz2" },
   { identifier = "pp37-macosx_x86_64", version = "3.7", url = "https://downloads.python.org/pypy/pypy3.7-v7.3.3-osx64.tar.bz2" },