another pylint stopIteration Runtime Error

[jbaum-cmcrc]

I'm seeing another "RuntimeError: generator raised StopIteration", similar to the already-fixed #2241.

Steps to reproduce

1. Make a file with the following contents:

class Foo:
    def __init__(self):
        self.count = 5 

    def bar(self):
        records = []
        for _ in []:
            records += []
        records = records[:self.count]
        records.sort()

2. Run pylint on the file

Current behavior

Throws exception:

************* Module pylint_bug
pylint_bug.py:1:0: C0111: Missing module docstring (missing-docstring)
pylint_bug.py:1:0: C0111: Missing class docstring (missing-docstring)
pylint_bug.py:5:4: C0102: Black listed name "bar" (blacklisted-name)
pylint_bug.py:5:4: C0111: Missing method docstring (missing-docstring)
Traceback (most recent call last):
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/inference.py", line 382, in infer_subscript
    assigned = value.getitem(index_value, context)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/node_classes.py", line 3609, in getitem
    return _container_getitem(self, self.elts, index, context=context)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/node_classes.py", line 204, in _container_getitem
    index_slice = _infer_slice(index, context=context)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/node_classes.py", line 187, in _infer_slice
    upper = _slice_value(node.upper, context)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/node_classes.py", line 171, in _slice_value
    inferred = next(index.infer(context=context))
StopIteration

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/jbaum/qq/venv-37/bin/pylint", line 11, in <module>
    sys.exit(run_pylint())
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/__init__.py", line 20, in run_pylint
    Run(sys.argv[1:])
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/lint.py", line 1608, in __init__
    linter.check(args)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/lint.py", line 938, in check
    self._do_check(files_or_modules)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/lint.py", line 1071, in _do_check
    self.check_astroid_module(ast_node, walker, rawcheckers, tokencheckers)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/lint.py", line 1154, in check_astroid_module
    walker.walk(ast_node)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/utils.py", line 1269, in walk
    self.walk(child)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/utils.py", line 1269, in walk
    self.walk(child)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/utils.py", line 1269, in walk
    self.walk(child)
  [Previous line repeated 1 more time]
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/utils.py", line 1266, in walk
    cb(astroid)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/checkers/typecheck.py", line 1035, in visit_call
    called = safe_infer(node.func)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/pylint/checkers/utils.py", line 1077, in safe_infer
    next(inferit)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/decorators.py", line 128, in raise_if_nothing_inferred
    yield next(generator)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/inference.py", line 290, in infer_attribute
    for owner in self.expr.infer(context):
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/decorators.py", line 128, in raise_if_nothing_inferred
    yield next(generator)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/bases.py", line 135, in _infer_stmts
    for inferred in stmt.infer(context=context):
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/decorators.py", line 128, in raise_if_nothing_inferred
    yield next(generator)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/bases.py", line 135, in _infer_stmts
    for inferred in stmt.infer(context=context):
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/jbaum/qq/venv-37/lib/python3.7/site-packages/astroid/decorators.py", line 128, in raise_if_nothing_inferred
    yield next(generator)
RuntimeError: generator raised StopIteration

Expected behavior

Normal pylint report.

pylint --version output

pylint 2.2.2
astroid 2.1.0
Python 3.7.1 (default, Oct 22 2018, 11:21:55)
[GCC 8.2.0]

[PCManticore]

Thanks, I can confirm the bug.

[PCManticore]

Thanks for the report @jbaum-cmcrc This does not reproduce any longer on the master branch of pylint using the latest astroid. I added a test to make sure we have a regression test in case the bug replicates in the future.

[jbaum-cmcrc]

Thank you!