Generic type-hinting for kwargs

I'm trying to wrap the signal class of blinker with one that enforces typing. The basic interface I'm trying to wrap is:

class Signal:  def send(self, sender: Any | None, **kwargs):    ...  def connect(self, receiver):    ...

(this isn't the exact interface but models the problem).

I can achieve type-hinting for the sender arg pretty simply using generics:

T = TypeVar("T")class TypedSignal(Generic[T], Signal):    def send(self, sender: Type[T], **kwargs):        super(TypedSignal, self).send(sender)    def connect(self, receiver: Callable[[Type[T], ...], None]) -> Callable:        return super(TypedSignal, self).connect(receiver)# used asmy_signal = TypedSignal[MyClass]()

what gets tricky is when I want to add type-checking for the kwargs. The approach I've been attempting to get working is using a variadic generic and Unpack like so:

T = TypeVar("T")KW = TypeVarTuple("KW")class TypedSignal(Generic[T, Unpack[KW]], Signal):    def send(self, sender: Type[T], **kwargs: Unpack[Type[KW]]):        super(TypedSignal, self).send(sender)    def connect(self, receiver: Callable[[Type[T], Unpack[Type[KW]]], None]) -> Callable:        return super(TypedSignal, self).connect(receiver)

but mypy complains: error: Unpack item in ** argument must be a TypedDict which seems odd because this error gets thrown even with no usage of the generic, let alone when a TypedDict is passed.

Is there a simpler way to do this? Is this possible with current python typing?

mypy version is 1.9.0 - tried with earlier versions and it crashed completely.