python3: fix stdenv bootstrap on x86_64-darwin

The bootstrap tools linker sometimes crashes when trying to link the
sqlite3 tests, which causes the bootstrap Python not to have the sqlite3
module. This causes the freezegun module to fail to build later in the
bootstrap. Using the 11.0 SDK fixes the problem.

Upstream Python supports building with a newer SDK and back-deploying,
so this change should not negatively affect users on pre-11.0 releases.

pkgs/development/interpreters/python/cpython/default.nix

@@ -25,6 +25,7 @@
 
 # platform-specific dependencies
 , bash
+, apple-sdk_11
 , darwin
 , windows
 
@@ -177,6 +178,9 @@ let
     bluez
   ] ++ optionals enableFramework [
     darwin.apple_sdk.frameworks.Cocoa
+  ] ++ optionals stdenv.hostPlatform.isDarwin [
+    # Work around for ld64 crashes on x86_64-darwin. Remove once 11.0 becomes the default.
+    apple-sdk_11
   ] ++ optionals stdenv.hostPlatform.isMinGW [
     windows.dlfcn
     windows.mingw_w64_pthreads

pkgs/stdenv/darwin/default.nix

@@ -648,6 +648,8 @@ assert bootstrapTools.passthru.isFromBootstrapFiles or false; # sanity check
           self = self.python3-bootstrap;
           pythonAttr = "python3-bootstrap";
           enableLTO = false;
+          # Workaround for ld64 crashes on x86_64-darwin. Remove after 11.0 is made the default.
+          inherit (prevStage) apple-sdk_11;
         };
 
         scons = super.scons.override { python3Packages = self.python3.pkgs; };