GeezerVison

In file included from ./Include/internal/pycore_backoff.h:12,
                 from ./Include/internal/pycore_code.h:11,
                 from ./Include/internal/pycore_call.h:11,
                 from ./Modules/_ctypes/_ctypes.c:109:
./Modules/_ctypes/_ctypes.c: In function ‘set_stginfo_ffi_type_pointer’:
./Modules/_ctypes/_ctypes.c:2234:40: error: ‘FFI_TYPE_COMPLEX’ undeclared (first use in this function); did you mean ‘FFI_TYPE_DOUBLE’?
         assert(fmt->pffi_type->type == FFI_TYPE_COMPLEX);
                                        ^~~~~~~~~~~~~~~~
./Modules/_ctypes/_ctypes.c:2234:40: note: each undeclared identifier is reported only once for each function it appears in

Traceback (most recent call last):
  File "/home/ubuntu/buildarea/pull_request.stan-aarch64-ubuntu.oddballs/build/Lib/test/pickletester.py", line 3254, in test_builtin_types
    s = self.dumps(t, proto)
  File "/home/ubuntu/buildarea/pull_request.stan-aarch64-ubuntu.oddballs/build/Lib/test/test_xpickle.py", line 190, in dumps
    return self.send_to_worker(python, data)
           ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
  File "/home/ubuntu/buildarea/pull_request.stan-aarch64-ubuntu.oddballs/build/Lib/test/test_xpickle.py", line 172, in send_to_worker
    raise exception
AttributeError: Can't get attribute 'sentinel' on <module 'builtins' (built-in)>

./python -m test test_xpickle -m test_builtin_types -u xpickle

diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index 6366f12257..c2018c9785 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -3244,6 +3244,7 @@ def test_builtin_types(self):
             'BuiltinImporter': (3, 3),
             'str': (3, 4),  # not interoperable with Python < 3.4
             'frozendict': (3, 15),
+            'sentinel': (3, 15),
         }
         for t in builtins.__dict__.values():
             if isinstance(t, type) and not issubclass(t, BaseException):