feat: add support for building iOS wheels. (#2286)

* Add support for building iOS wheels.

* Replace use of system() in test binary module.

* Restored the 'minimal' approach of the minimal examples.

* Split out platform details into standalone pages, and expand iOS platform details.

* More doc corrections.

* Bump support package to include fix for python/cpython#130292

* Ensure iOS tests are all run on the same xdist worker.

* More iOS documentation tweaks.

* Factor out common xcode version test utility.

* Simplify iOS to a single platform with an expanded interpretation of arch.

* I guess I should update the iOS tests as well...

* Additional safety for missing iOS test output.

* Remove DYLD_LIBRARY_PATH from the iOS environment.

* Make test-sources mandatory for iOS builds.

* Updates and clarifications to documentation.

* Clarify what a slice is.

* Normalize use of underscores in platform name.

* Modify auto target to be matching CPU only.

* Use consistent ordering of platforms in examples.

* Use consistent naming in iOS archiectures.

* Placate the linter.

* Miscellaneous cleanups picked up by @joerick's review.

* Correct the list of expected wheels.

* Correct which 'native' we're actually checking.

* Correct the docs links so they're all relative.

* Correct the identification of free threaded builds.

* Use target instead of host to describe the platform we're building for.

* Rework iOS test to remove issue with log completeness.

* Convert errors to FatalError

Co-authored-by: Matthieu Darbois <mayeut@users.noreply.github.com>
Co-authored-by: Joe Rickerby <joerick@mac.com>

* Removed a repeated check for a valid python.

* Update bin/update_pythons.py to update iOS support packages.

* Document that iOS CI is available on other platforms.

* Restore a comment needed for some platforms.

* Small cleanups identified in code review

Co-authored-by: Joe Rickerby <joerick@mac.com>

* Simplify logic to appease linter.

* Modify dependency constraint handling to use new API.

* Cosmetic change to trigger a CI rebuild.

---------

Co-authored-by: Matthieu Darbois <mayeut@users.noreply.github.com>
Co-authored-by: Joe Rickerby <joerick@mac.com>

cibuildwheel/__main__.py

@@ -15,6 +15,7 @@ from tempfile import mkdtemp
 from typing import Any, Protocol, TextIO, assert_never
 
 import cibuildwheel
+import cibuildwheel.ios
 import cibuildwheel.linux
 import cibuildwheel.macos
 import cibuildwheel.pyodide
@@ -93,13 +94,14 @@ def main_inner(global_options: GlobalOptions) -> None:
 
     parser.add_argument(
         "--platform",
-        choices=["auto", "linux", "macos", "windows", "pyodide"],
+        choices=["auto", "linux", "macos", "windows", "pyodide", "ios"],
         default=None,
         help="""
-            Platform to build for. Use this option to override the
-            auto-detected platform. Specifying "macos" or "windows" only works
-            on that operating system, but "linux" works on all three, as long
-            as Docker/Podman is installed. Default: auto.
+            Platform to build for. Use this option to override the auto-detected
+            platform. Specifying "macos" or "windows" only works on that
+            operating system. "linux" works on any desktop OS, as long as
+            Docker/Podman is installed. "pyodide" only works on linux and macOS.
+            "ios" only work on macOS. Default: auto.
         """,
     )
 
@@ -240,6 +242,8 @@ def _compute_platform_only(only: str) -> PlatformName:
         return "windows"
     if "pyodide_" in only:
         return "pyodide"
+    if "ios_" in only:
+        return "ios"
     msg = f"Invalid --only='{only}', must be a build selector with a known platform"
     raise errors.ConfigurationError(msg)
 
@@ -301,6 +305,8 @@ def get_platform_module(platform: PlatformName) -> PlatformModule:
         return cibuildwheel.macos
     if platform == "pyodide":
         return cibuildwheel.pyodide
+    if platform == "ios":
+        return cibuildwheel.ios
     assert_never(platform)