Incorrect type annotations for signal handlers

[9999years]

In signal.pyi:83, signal handlers are typed as:

_HANDLER = Union[Callable[[Signals, FrameType], Any], int, Handlers, None]

But I think this might be more accurate:

_HANDLER = Union[Callable[[int, Optional[FrameType]], Any], int, Handlers, None]

The documentation for signal.signal points out that the current annotation might be wrong (emphasis my own):

The handler is called with two arguments: the signal number and the current stack frame (None or a frame object; for a description of frame objects, see the description in the type hierarchy or see the attribute descriptions in the inspect module).

And when we use them, we can see that the signal number is passed as an int, not a signal.Signals member:

import signal

def handler(signal_number, frame):
    print("In signal handler!")
    print("Signal number:", signal_number, type(signal_number))
    print("Stack frame:  ", frame, type(frame))

# Set signal handler:
signal.signal(signal.SIGHUP, handler)

# Use it:
signal.raise_signal(signal.SIGHUP)

Which prints:

In signal handler!
Signal number: 1 <class 'int'>
Stack frame:   <frame at 0x7f804402abe0, file '<stdin>', line 12, code <module>> <class 'frame'>