NameInferenceError

[owillebo]

Steps to reproduce

lint following code;

if len(dont_care[0]):
    pass

Current behavior

pylint crashes;

************* Module bug

bug.py:1:0: [C0114] Missing module docstring (missing-module-docstring)
Traceback (most recent call last):
  File "c:\program files\python39\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "c:\program files\python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Program Files\Python39\Scripts\pylint.exe\__main__.py", line 7, in <module>
  File "c:\program files\python39\lib\site-packages\pylint\__init__.py", line 22, in run_pylint
    PylintRun(sys.argv[1:])
  File "c:\program files\python39\lib\site-packages\pylint\lint\run.py", line 358, in __init__
    linter.check(args)
  File "c:\program files\python39\lib\site-packages\pylint\lint\pylinter.py", line 862, in check
    self._check_files(
  File "c:\program files\python39\lib\site-packages\pylint\lint\pylinter.py", line 896, in _check_files
    self._check_file(get_ast, check_astroid_module, name, filepath, modname)
  File "c:\program files\python39\lib\site-packages\pylint\lint\pylinter.py", line 922, in _check_file
    check_astroid_module(ast_node)
  File "c:\program files\python39\lib\site-packages\pylint\lint\pylinter.py", line 1054, in check_astroid_module
    retval = self._check_astroid_module(
  File "c:\program files\python39\lib\site-packages\pylint\lint\pylinter.py", line 1099, in _check_astroid_module
    walker.walk(ast_node)
  File "c:\program files\python39\lib\site-packages\pylint\utils\ast_walker.py", line 75, in walk
    self.walk(child)
  File "c:\program files\python39\lib\site-packages\pylint\utils\ast_walker.py", line 75, in walk
    self.walk(child)
  File "c:\program files\python39\lib\site-packages\pylint\utils\ast_walker.py", line 72, in walk
    callback(astroid)
  File "c:\program files\python39\lib\site-packages\pylint\checkers\refactoring\len_checker.py", line 76, in visit_call
    instance = next(len_arg.infer())
  File "c:\program files\python39\lib\site-packages\astroid\node_classes.py", line 366, in infer
    yield from self._infer(context, **kwargs)
  File "c:\program files\python39\lib\site-packages\astroid\decorators.py", line 135, in raise_if_nothing_inferred
    yield next(generator)
  File "c:\program files\python39\lib\site-packages\astroid\decorators.py", line 99, in wrapped
    res = next(generator)
  File "c:\program files\python39\lib\site-packages\astroid\inference.py", line 368, in infer_subscript
    for value in self.value.infer(context):
  File "c:\program files\python39\lib\site-packages\astroid\node_classes.py", line 380, in infer
    for i, result in enumerate(generator):
  File "c:\program files\python39\lib\site-packages\astroid\decorators.py", line 135, in raise_if_nothing_inferred
    yield next(generator)
  File "c:\program files\python39\lib\site-packages\astroid\decorators.py", line 96, in wrapped
    generator = _func(node, context, **kwargs)
  File "c:\program files\python39\lib\site-packages\astroid\inference.py", line 201, in infer_name
    raise exceptions.NameInferenceError(
astroid.exceptions.NameInferenceError: 'dont_care' not found in <Module.bug l.0 at 0x1a3f69f5310>.

Expected behavior

Just print some warnings.

pylint --version output

pylint 2.7.2
astroid 2.5.1
Python 3.9.2 (tags/v3.9.2:1a79785, Feb 19 2021, 13:44:55) [MSC v.1928 64 bit (AMD64)]

[cdce8p]

I've opened #4216 to fix it

[owillebo]

See for consequential damage of this issue #4165.