Support building x86-64 wheel on arm64 macOS machine (#114)

Co-authored-by: David Hewitt <[email protected]>

Author: messense

CHANGELOG.md

@@ -4,6 +4,9 @@
 ### Packaging
 - Bump minimum Python version to Python 3.6.
 
+### Added
+- Support building x86-64 wheel on arm64 macOS machine. [#114](https://github.com/PyO3/setuptools-rust/pull/114)
+
 ### Changed
 - Respect `PYO3_PYTHON` and `PYTHON_SYS_EXECUTABLE` environment variables if set. [#96](https://github.com/PyO3/setuptools-rust/pull/96)
 - Add runtime dependency on setuptools >= 46.1. [#102](https://github.com/PyO3/setuptools-rust/pull/102)

setuptools_rust/build.py

@@ -1,6 +1,7 @@
 import glob
 import json
 import os
+import platform
 import shutil
 import sys
 import subprocess
@@ -95,6 +96,9 @@ def run_for_extension(self, ext: RustExtension):
             target_triple = "i686-pc-windows-msvc"
         elif self.plat_name == "win-amd64":
             target_triple = "x86_64-pc-windows-msvc"
+        elif self.plat_name.startswith("macosx-") and platform.machine() == "x86_64":
+            # x86_64 or arm64 macOS targeting x86_64
+            target_triple = "x86_64-apple-darwin"
 
         if target_triple is not None:
             target_args = ["--target", target_triple]