Cannot pass kwargs through for functions with default argument

[pedroceles]

First, thanks a lot for this library!

This bug is probably related to #1969

def test1(**kwargs: int) -> None:
    test2(**kwargs)

def test2(a: bool=True, **kwargs: int) -> None:
    print(a, kwargs)

results in this error:

test_mypy.py:2: error: Argument 1 to "test2" has incompatible type "**Dict[str, int]"; expected "bool"

The inconvenient fix would be:

from typing import Mapping

def test1(**kwargs: int) -> None:
    temp = kwargs  # type: Mapping[str, int]
    test2(**temp)

def test2(a: bool=True, **kwargs: int) -> None:
    print(a, kwargs)

Python version: 3.5.3
Mypy version: 0.740

mypy.ini

[mypy]
python_version = 3.5
warn_return_any = True
warn_unused_configs = True
disallow_incomplete_defs = True
disallow_untyped_defs = True

[JelleZijlstra]

I think mypy is right here: the code is unsafe. If you call test1(a=1), test2 would receive an int instead of a bool for its a parameter.

[ilevkivskyi]

I think mypy is right here: the code is unsafe.

Yes, this code is technically unsafe, the error message is cryptic however, but we already have an issue to make it better, see #5382

[pedroceles]

If that is the case there should be an error raised in the second example as well, shouldn't it?

[ilevkivskyi]

If that is the case there should be an error raised in the second example as well, shouldn't it?

Yes, I am however not super worried about the inconsistency. You may open an issue about this however if you want to prohibit this (or retitle this one).