During metaclass.__init__, super() of the constructed class does not work

Lib/importlib/_bootstrap_external.py

 """Core implementation of path-based import.
 
 This module is NOT meant to be directly imported! It has been designed such
 that it can be bootstrapped into Python as the implementation of import. As
 such it requires the injection of specific modules and attributes in order to
 work. One should use importlib as the public-facing version of this module.
 
 """
 #
 # IMPORTANT: Whenever making changes to this module, be sure to run
@@ skipping 221 matching lines @@
 #     Python 3.6a1  3370 (16 bit wordcode)
 #     Python 3.6a1  3371 (add BUILD_CONST_KEY_MAP opcode #27140)
 #     Python 3.6a1  3372 (MAKE_FUNCTION simplification, remove MAKE_CLOSURE
 #                         #27095)
 #     Python 3.6b1  3373 (add BUILD_STRING opcode #27078)
 #     Python 3.6b1  3375 (add SETUP_ANNOTATIONS and STORE_ANNOTATION opcodes
 #                         #27985)
 #     Python 3.6b1  3376 (simplify CALL_FUNCTIONs & BUILD_MAP_UNPACK_WITH_CALL)
 #     Python 3.6b1  3377 (set __class__ cell from type.__new__ #23722)
 #     Python 3.6b2  3378 (add BUILD_TUPLE_UNPACK_WITH_CALL #28257)
+#     Python 3.6rc1 3379 (more thorough __class__ validation #23722)
 #
 # MAGIC must change whenever the bytecode emitted by the compiler may no
 # longer be understood by older implementations of the eval loop (usually
 # due to the addition of new opcodes).
 #
 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.
 
-MAGIC_NUMBER = (3378).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3379).to_bytes(2, 'little') + b'\r\n'
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 
 _PYCACHE = '__pycache__'
 _OPT = 'opt-'
 
 SOURCE_SUFFIXES = ['.py']  # _setup() adds .pyw as needed.
 
 BYTECODE_SUFFIXES = ['.pyc']
 # Deprecated.
 DEBUG_BYTECODE_SUFFIXES = OPTIMIZED_BYTECODE_SUFFIXES = BYTECODE_SUFFIXES
@@ skipping 1174 matching lines @@
 
 
 def _install(_bootstrap_module):
     """Install the path-based import components."""
     _setup(_bootstrap_module)
     supported_loaders = _get_supported_file_loaders()
     sys.path_hooks.extend([FileFinder.path_hook(*supported_loaders)])
     if _os.__name__ == 'nt':
         sys.meta_path.append(WindowsRegistryFinder)
     sys.meta_path.append(PathFinder)