Bogus C0202, E0213 warnings when using positional-only parameters (PEP 570)

[scottj97]

Steps to reproduce

Run pylint on the following file:

#!python3
"""Test linting.

This is only intended to test pylint support for python 3.8's
positional-only arguments (PEP 570).
"""


class Foobar:
    """Class for frobulating the Foobar."""

    @classmethod
    def buildme(cls, /, value):
        """Construct object using alternate method."""
        return cls(value).abc

    def runme(self, qrs, /, xyz=None):
        """Do something funcy."""
        if self.abc and qrs and xyz:
            print("found something else")

Current behavior

************* Module run
src/run.py:14:4: C0202: Class method buildme should have 'cls' as first argument (bad-classmethod-argument)
src/run.py:18:4: E0213: Method should have "self" as first argument (no-self-argument)

------------------------------------------------------------------
Your code has been rated at 0.00/10 (previous run: 0.00/10, +0.00)

Expected behavior

No warnings.

pylint --version output

pylint 2.5.0-dev1
astroid 2.3.2
Python 3.8.0 (default, Oct 25 2019, 11:21:45) 
[GCC 8.2.0]

I'm running pylint from github at ee8bd98.

Since the pylint README says to use the latest astroid, I tried that too, requiring a change to pylint/__pkginfo__.py to allow the latest version (7aca7d4726c6f6ae8cf720fc95ecc8fb0ad246d5). The bogus warnings were still there.

Related issues

#3161
PyCQA/pep8-naming#122

[PCManticore]

Thanks for the report! This is now fixed in master.

[scottj97]

I confirm this fixes the issues I was seeing. Thanks for the quick patch!