--- setup.py.orig	2020-11-24 06:08:38.000000000 -0800
+++ setup.py	2020-12-10 22:04:28.000000000 -0800
@@ -109,9 +109,6 @@
     return config.try_compile('#ifndef _MSC_VER\n#error "not MSVC"\n#endif')
 
 def use_pkg_config():
-    if sys.platform == 'darwin' and os.path.exists('/usr/local/bin/brew'):
-        use_homebrew_for_libffi()
-
     _ask_pkg_config(include_dirs,       '--cflags-only-I', '-I', sysroot=True)
     _ask_pkg_config(extra_compile_args, '--cflags-only-other')
     _ask_pkg_config(library_dirs,       '--libs-only-L', '-L', sysroot=True)
@@ -153,10 +150,6 @@
     ask_supports_thread()
     ask_supports_sync_synchronize()
 
-if 'darwin' in sys.platform:
-    # priority is given to `pkg_config`, but always fall back on SDK's libffi.
-    extra_compile_args += ['-iwithsysroot/usr/include/ffi']
-
 if 'freebsd' in sys.platform:
     include_dirs.append('/usr/local/include')
     library_dirs.append('/usr/local/lib')