Mypy error when dealing with Generic classes, class variables and staticmethod

Question

I have the following code that replicates an error that I have in my original code:

from typing import Generic, TypeVar, ClassVar, Type
from abc import ABC, abstractmethod

T = TypeVar("T")

class Formatter(ABC, Generic[T]):
  @staticmethod
  @abstractmethod
  def format(x: T) -> T:
    ...

class MyFormatter(Formatter[T]):
  @staticmethod
  def format(x: T) -> T:
    return x


class FormattableClass(ABC, Generic[T]):
  formatter: ClassVar[Type[Formatter]]
  def __init__(self, x: T) -> None:
    self.x: T = x

class SpecificFormattableClass(FormattableClass[T]):
  formatter = MyFormatter
  def __init__(self, x: T):
    self.x = self.formatter.format(x)

Mypy shows the following error in the last line

Incompatible types in assignment (expression has type "T", variable has type "T")

How should I procede to solve it then?

I know it may be from the fact that mypy cannot know that "T" in the Formatter class is the same T as the FormattableClass generic. A possible solution I came up was simply do the following:

class FormattableClass(ABC, Generic[T]):
-  formatter: ClassVar[Type[Formatter]]
+  formatter: ClassVar[Type[Formatter[T]]]
  def __init__(self, x: T) -> None:
    self.x: T = x

But mypy complains about another error

ClassVar cannot contain type variables