error: Cannot determine type of 'f3'

[wugifer]

When I mix codes with 'import loop', 'class decorator', sometimes mypy cannot determine my function type:

$ mypy level1.py
level2.py:3: error: Cannot determine type of 'f3'

but run python ok:

$ python3 level1.py
$

Below are my codes:

$ cat level1.py
import  level2

$ cat level2.py
import level3

f3 = level3.f3

$ cat level3.py
from level4 import v4

class C3(object):
    def deco(self, func):
        def new_func():
            pass

        return new_func

obj = C3()

@obj.deco
def f3():
    pass

$ cat level4.py
import level2

v4 = 4

I have do some tests, here are the results:

• level4.py removes 'v4=4', level3.py changes to 'import level4', mypy ok
• level4.py removes 'import level2', mypy ok
• level2.py changes to 'from level3 import f3', mypy ok
• level3.py changes to non-class decorator, mypy ok

[ilevkivskyi]

Thanks for reporting! I think this is a duplicate of #6356