From 8c363a53d48ea68c9df913f344dd0b9fee34896f Mon Sep 17 00:00:00 2001
From: Isuru Fernando <isuruf@gmail.com>
Date: Mon, 25 Jan 2021 03:28:08 -0600
Subject: [PATCH 18/25] Make dyld search work with SYSTEM_VERSION_COMPAT=1

In macOS Big Sur, if the executable was compiled with `MACOSX_DEPLOYMENT_TARGET=10.15`
or below, then SYSTEM_VERSION_COMPAT=1 is the default which means that Big Sur
reports itself as 10.16 which means that `__builtin_available(macOS 11.0)` will not be triggered.

This can be observed by using the python 3.9.1 universal2 installer and using it on
x86_64 Big Sur or with Rossetta 2 on arm64 Big Sur. (Not an issue with native arm64
as that part is compiled with `MACOSX_DEPLOYMENT_TARGET=11.0`)
---
 Modules/_ctypes/callproc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index 48694760db..e72352ffac 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -1445,7 +1445,7 @@ copy_com_pointer(PyObject *self, PyObject *args)
 #ifdef __APPLE__
 #ifdef HAVE_DYLD_SHARED_CACHE_CONTAINS_PATH
 #define HAVE_DYLD_SHARED_CACHE_CONTAINS_PATH_RUNTIME \
-    __builtin_available(macOS 11.0, iOS 14.0, tvOS 14.0, watchOS 7.0, *)
+    __builtin_available(macOS 10.16, iOS 14.0, tvOS 14.0, watchOS 7.0, *)
 #else
 // Support the deprecated case of compiling on an older macOS version
 static void *libsystem_b_handle;
-- 
2.32.1 (Apple Git-133)

