Incorrect "undefined variable" error for class variables as return type annotations

[nicktimko]

pylint seems to incorrectly identify an undefined variable error when using a class variable as a return type annotation. Argument type annotations appear to be OK.

Steps to reproduce

# lintcheck.py
class MyObject:
    class MyType:
        pass
    def my_method(self) -> MyType:
        pass

Current behavior

$ pylint lintcheck.py -E
No config file found, using default configuration
************* Module lintcheck
E:  5,27: Undefined variable 'MyType' (undefined-variable)

Expected behavior

No error.

Curiously, the below doesn't emit any errors, where MyType should have identical scope:

# lintcheck_ok.py
class MyObject2:
    class MyType:
        pass
    def my_method(self, x: MyType):
        pass
    def my_thing(self, x=MyType):
        pass

pylint --version output

$ pylint --version
No config file found, using default configuration
pylint 1.8.3, 
astroid 1.6.2
Python 3.6.4 (default, Mar 26 2018, 16:21:07) 
[GCC 5.4.0 20160609]

[PCManticore]

Thanks, I can reproduce the issue!

[pt12lol]

Another test case: https://stackoverflow.com/questions/61271870/methods-decorator-parameter-cannot-be-a-list-comprehension-based-on-class-stat

[failable]

I can't get this work

class Dataset(object):
    T = TypeVar("T", bound="Dataset")

    @classmethod
    def from_dir(cls: Type[T], dirname: str) -> T:                    # Undefined variable 'T'
        ...

Am I doing wrong? Thanks!

[zhiltsov-max]

The same thing for

class Project:
    MyType = NewType('MyType', str)

    def foo(self, obj: MyType):                    # Undefined variable 'MyType'