--- a/llvm/lib/Support/Unix/Path.inc	2020-02-17 09:24:26.000000000 +0100
+++ b/llvm/lib/Support/Unix/Path.inc	2020-02-17 09:26:25.000000000 +0100
@@ -1200,7 +1200,9 @@
 /// implementation.
 std::error_code copy_file(const Twine &From, const Twine &To) {
   uint32_t Flag = COPYFILE_DATA;
-#if __has_builtin(__builtin_available) && defined(COPYFILE_CLONE)
+  // BLENDER: This optimization makes LLVM not build on older Xcode versions,
+  // just disable until everyone has new enough Xcode versions.
+#if 0
   if (__builtin_available(macos 10.12, *)) {
     bool IsSymlink;
     if (std::error_code Error = is_symlink_file(From, IsSymlink))
