Crash due to Uninferable type

[swails]

Steps to reproduce

I'm not sure exactly where the code that is breaking pylint is located

Current behavior

pylint crashes:

Fixes this bug in pylint:

Traceback (most recent call last):
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/__init__.py", line 93, in _inference_tip_cached
    return iter(_cache[func, node])
KeyError: (<function register_builtin_transform.<locals>._transform_wrapper at 0x7f9bd8b34040>, <Call l.281 at 0x7f9bd3b28340>)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/scratch2/anaconda3/envs/entos/bin/pylint", line 11, in <module>
    sys.exit(run_pylint())
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/__init__.py", line 22, in run_pylint
    PylintRun(sys.argv[1:])
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/lint/run.py", line 349, in __init__
    linter.check(args)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/lint/pylinter.py", line 862, in check
    self._check_files(
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/lint/pylinter.py", line 896, in _check_files
    self._check_file(get_ast, check_astroid_module, name, filepath, modname)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/lint/pylinter.py", line 922, in _check_file
    check_astroid_module(ast_node)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/lint/pylinter.py", line 1054, in check_astroid_module
    retval = self._check_astroid_module(
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/lint/pylinter.py", line 1099, in _check_astroid_module
    walker.walk(ast_node)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/utils/ast_walker.py", line 75, in walk
    self.walk(child)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/utils/ast_walker.py", line 75, in walk
    self.walk(child)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/utils/ast_walker.py", line 72, in walk
    callback(astroid)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/checkers/classes.py", line 1866, in visit_functiondef
    inferred = _safe_infer_call_result(node, node)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/pylint/checkers/classes.py", line 449, in _safe_infer_call_result
    next(inferit)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/scoped_nodes.py", line 1722, in infer_call_result
    yield from returnnode.value.infer(context)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/node_classes.py", line 357, in infer
    return self._explicit_inference(self, context, **kwargs)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/__init__.py", line 95, in _inference_tip_cached
    result = func(*args, **kwargs)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/brain/brain_builtin_inference.py", line 135, in _transform_wrapper
    result = transform(node, context=context)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/brain/brain_builtin_inference.py", line 219, in _infer_builtin_container
    return _container_generic_inference(node, context, klass, transform_func)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/brain/brain_builtin_inference.py", line 172, in _container_generic_inference
    transformed = transform(inferred)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/brain/brain_builtin_inference.py", line 188, in _container_generic_transform
    inferred = helpers.safe_infer(element, context=context)
  File "/scratch2/anaconda3/envs/entos/lib/python3.8/site-packages/astroid/helpers.py", line 153, in safe_infer
    value = next(inferit)
TypeError: 'Uninferable' object is not an iterator

Expected behavior

pylint finishes normally

python -c "from astroid import __pkginfo__; print(__pkginfo__.version)" output

2.4.2

[PCManticore]

Thanks for the report. Unfortunately it's really hard to figure out what went wrong here without a reproduction example. Is it possible to reduce the code that leads to the crash to a minimal example? That should give us at least an idea on where to look.

[PCManticore]

This will be fixed by #876. Thanks for the report.