# Buggy code
def build_cfg(cls, code_obj, *args, **kws):
    ret_val = cls(*args, **kws)
    opmap = opcode.opname
    ret_val.crnt_block = 0
    ret_val.code_len = len(code_obj.co_code)
    ret_val.add_block(0)
    ret_val.blocks_writes[0] = set(range(code_obj.co_argcount))
    last_was_jump = True  # At start there is no prior basic block
    # to link up with, so skip building a
    # fallthrough edge.
    for i, op, arg in itercode(code_obj.co_code):
        if i in ret_val.blocks:
            if not last_was_jump:
                ret_val.add_edge(ret_val.crnt_block, i)
            ret_val.crnt_block = i
        last_was_jump = False
        method_name = "op_" + opmap[op]
        if hasattr(ret_val, method_name):
            last_was_jump = getattr(ret_val, method_name)(i, op, arg)
    del ret_val.crnt_block, ret_val.code_len
    return ret_val


# Traceback (TypeError)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-15-3b23f7331ceb> in <module>()
----> 1 @jit(arg_types=[numba.double], ret_type=numba.double)
2 def is_REALLY_five(some_value):
3     for i in range(5):
4         if some_value == 5.0:
5             return 1.0

/Library/Frameworks/EPD64.framework/Versions/7.3/lib/python2.7/site-packages/numba/decorators.pyc in _jit(func)
77                   "garbage collected!" % (func,))
78         t = Translate(func, *args, **kws)
---> 79         t.translate()
80         __tr_map__[func] = t
81         return t.get_ctypes_func(llvm)

/Library/Frameworks/EPD64.framework/Versions/7.3/lib/python2.7/site-packages/numba/translate.pyc in translate(self)
926                     # Ensure we are playing with locals that might
927                     # actually precede the next block.
--> 928                     self.check_locals(i)
929
930                 self.crnt_block = i

/Library/Frameworks/EPD64.framework/Versions/7.3/lib/python2.7/site-packages/numba/translate.pyc in check_locals(self, i)
1135                 else:
1136                     assert next_locals is not None, "Internal compiler error!"
-> 1137             self._locals = next_locals[:]
1138
1139     def get_ctypes_func(self, llvm=True):

TypeError: 'NoneType' object has no attribute '__getitem__'

# Fixed code
def build_cfg(cls, code_obj, *args, **kws):
    ret_val = cls(*args, **kws)
    opmap = opcode.opname
    ret_val.crnt_block = 0
    ret_val.code_len = len(code_obj.co_code)
    ret_val.add_block(0)
    ret_val.blocks_writes[0] = set(range(code_obj.co_argcount))
    last_was_jump = True  # At start there is no prior basic block
    # to link up with, so skip building a
    # fallthrough edge.
    for i, op, arg in itercode(code_obj.co_code):
        if i in ret_val.blocks:
            if not last_was_jump:
                ret_val.add_edge(ret_val.crnt_block, i)
            ret_val.crnt_block = i
        last_was_jump = False
        method_name = "op_" + opmap[op]
        if hasattr(ret_val, method_name):
            last_was_jump = getattr(ret_val, method_name)(i, op, arg)
    ret_val.unlink_unreachables()
    del ret_val.crnt_block, ret_val.code_len
    return ret_val