Pylint: astroid.exceptions.InferenceError: Empty return iterator

[poncovka]

Steps to reproduce

Pylint fails with a traceback when we try to analyze anaconda.

The problem seems to be in this file, but I don't know where to look for the main cause:
https://github.com/rhinstaller/anaconda/blob/modularization-devel/pyanaconda/payload/livepayload.py

Current behavior

Traceback (most recent call last):
  File "/usr/bin/pylint-3", line 11, in <module>
    load_entry_point('pylint==2.0.0', 'console_scripts', 'pylint')()
  File "/usr/lib/python3.7/site-packages/pylint/__init__.py", line 19, in run_pylint
    Run(sys.argv[1:])
  File "/usr/lib/python3.7/site-packages/pylint/lint.py", line 1394, in __init__
    linter.check(args)
  File "/usr/lib/python3.7/site-packages/pylint/lint.py", line 801, in check
    self._do_check(files_or_modules)
  File "/usr/lib/python3.7/site-packages/pylint/lint.py", line 938, in _do_check
    self.check_astroid_module(ast_node, walker, rawcheckers, tokencheckers)
  File "/usr/lib/python3.7/site-packages/pylint/lint.py", line 1018, in check_astroid_module
    walker.walk(ast_node)
  File "/usr/lib/python3.7/site-packages/pylint/utils.py", line 1159, in walk
    self.walk(child)
  File "/usr/lib/python3.7/site-packages/pylint/utils.py", line 1159, in walk
    self.walk(child)
  File "/usr/lib/python3.7/site-packages/pylint/utils.py", line 1159, in walk
    self.walk(child)
  [Previous line repeated 1 more times]
  File "/usr/lib/python3.7/site-packages/pylint/utils.py", line 1156, in walk
    cb(astroid)
  File "/usr/lib/python3.7/site-packages/pylint/checkers/typecheck.py", line 748, in visit_attribute
    if not [n for n in owner.getattr(node.attrname)
  File "/usr/lib/python3.7/site-packages/astroid/objects.py", line 181, in getattr
    return list(self.igetattr(name, context=context))
  File "/usr/lib/python3.7/site-packages/astroid/objects.py", line 170, in igetattr
    for value in inferred.infer_call_result(self, context):
  File "/usr/lib/python3.7/site-packages/astroid/scoped_nodes.py", line 1621, in infer_call_result
    raise exceptions.InferenceError('Empty return iterator')
astroid.exceptions.InferenceError: Empty return iterator

Expected behavior

No traceback.

pylint --version output

pylint 2.0.0
astroid 2.0
Python 3.7.0 (default, Jul 15 2018, 06:08:44)
[GCC 8.1.1 20180626 (Red Hat 8.1.1-4)]

[brycepg]

I'm having trouble reproducing. Can you give me a pip freeze of your installed packages? + anaconda commit hash?

[elpollouk]

I've reproduced this error in the following version:

C:\Temp> py -3 -m pylint --version
__main__.py 2.0.1
astroid 2.0.1
Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)]

It seems to be related to fetching properties through super() that were initially defined on an abstract base class. The code to reproduce it is:

from abc import ABC, abstractmethod

class MyBaseABC(ABC):
    @property
    @abstractmethod
    def prop(self):
        """Example property"""

class MyBase(MyBaseABC):
    @property
    def prop(self):
        return 11

class MyChild(MyBase):
    @property
    def prop(self):
        return super().prop + 2

c = MyChild()
print(c.prop)

To reproduce the error, save the above code snippet as test.py and run:
py -3 -m pylint test.py

[brycepg]

Thanks @elpollouk! I can reproduce on master

[PCManticore]

Thanks folks for the reproducing example! This should be fixed now in astroid's master. If I'll find some time this week, I'll do a 2.1 release.

[pzelnip]

This appears to have been fixed (or at least was for my case) with Pylint 2.1. Thanks very much for the prompt fix!

[elpollouk]

Yep, updateing to Pylint 2.1.0 and asteroid 2.0.2 has solved this for me as well.

Thanks very much for the quick resolution.