RuntimeError: generator raised StopIteration

[JustKiddingCode]

I have the error bellow when using dataclasses with replace and pylint.
I think it has something todo with the key access, when I'm using a normal (emtpy) dict
pylint doesn't throw an error.

Steps to reproduce

Use this example:

from dataclasses import dataclass, field, replace
from typing import List

def default_redirect():
    return []

@dataclass
class ProxyConfig:
    """ Configuration for the Proxy Setup """
    keyfile: str
    certfile: str
    domainname: str
    contacts: List[str]
    address: str = "0.0.0.0"
    tls_port: int = 443
    plain_port: int = 80
    https_only: bool = True
    username: str = "www-data"
    groupname: str = "www-data"
    secrets: str = "/var/lib/oidc-proxy/secrets.yml"
    tls_redirect: str = "/TLSRedirect"
    auth: str = "/auth"
    redirect: List[str] = field(default_factory=default_redirect)
    plugin_dirs: List[str] = field(default_factory=list)


a = ProxyConfig("", "", "", [""])
test_dict = {"proxy" : {}}

a = replace(a, **test_dict['proxy'])

Run with pylint

Current behavior

************* Module test
/tmp/tmp.9j0R7c2kjs/test.py:1:0: C0114: Missing module docstring (missing-module-docstring)
/tmp/tmp.9j0R7c2kjs/test.py:4:0: C0116: Missing function or method docstring (missing-function-docstring)
/tmp/tmp.9j0R7c2kjs/test.py:7:0: R0902: Too many instance attributes (15/7) (too-many-instance-attributes)
Traceback (most recent call last):
  File "/home/justkidding/git/astroid/astroid/protocols.py", line 337, in _arguments_infer_argname
    call_site = arguments.CallSite(context.callcontext, context.extra_context)
  File "/home/justkidding/git/astroid/astroid/arguments.py", line 43, in __init__
    self._unpacked_kwargs = self._unpack_keywords(keywords, context=context)
  File "/home/justkidding/git/astroid/astroid/arguments.py", line 96, in _unpack_keywords
    inferred = next(value.infer(context=context))
StopIteration

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

Traceback (most recent call last):
  File "/home/justkidding/.local/share/virtualenvs/pylint-b0C_0gT4/bin/pylint", line 7, in <module>
    exec(compile(f.read(), __file__, 'exec'))
  File "/home/justkidding/git/pylint/bin/pylint", line 4, in <module>
    run_pylint()
  File "/home/justkidding/git/pylint/pylint/__init__.py", line 22, in run_pylint
    PylintRun(sys.argv[1:])
  File "/home/justkidding/git/pylint/pylint/lint.py", line 1770, in __init__
    linter.check(args)
  File "/home/justkidding/git/pylint/pylint/lint.py", line 980, in check
    self._check_files(self.get_ast, self._iterate_file_descrs(files_or_modules))
  File "/home/justkidding/git/pylint/pylint/lint.py", line 1009, in _check_files
    self._check_file(get_ast, check_astroid_module, name, filepath, modname)
  File "/home/justkidding/git/pylint/pylint/lint.py", line 1035, in _check_file
    check_astroid_module(ast_node)
  File "/home/justkidding/git/pylint/pylint/lint.py", line 1168, in check_astroid_module
    ast_node, walker, rawcheckers, tokencheckers
  File "/home/justkidding/git/pylint/pylint/lint.py", line 1212, in _check_astroid_module
    walker.walk(ast_node)
  File "/home/justkidding/git/pylint/pylint/utils/ast_walker.py", line 77, in walk
    self.walk(child)
  File "/home/justkidding/git/pylint/pylint/utils/ast_walker.py", line 77, in walk
    self.walk(child)
  File "/home/justkidding/git/pylint/pylint/utils/ast_walker.py", line 74, in walk
    callback(astroid)
  File "/home/justkidding/git/pylint/pylint/checkers/base.py", line 1938, in visit_assignname
    if isinstance(utils.safe_infer(assign_type.value), astroid.ClassDef):
  File "/home/justkidding/git/pylint/pylint/checkers/utils.py", line 1105, in safe_infer
    for inferred in infer_gen:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 141, in raise_if_nothing_inferred
    yield from generator
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/justkidding/git/astroid/astroid/inference.py", line 229, in infer_call
    yield from callee.infer_call_result(caller=self, context=callcontext)
  File "/home/justkidding/git/astroid/astroid/scoped_nodes.py", line 1706, in infer_call_result
    yield from returnnode.value.infer(context)
  File "/home/justkidding/git/astroid/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/justkidding/git/astroid/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 141, in raise_if_nothing_inferred
    yield from generator
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/justkidding/git/astroid/astroid/inference.py", line 223, in infer_call
    for callee in self.func.infer(context):
  File "/home/justkidding/git/astroid/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/justkidding/git/astroid/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 141, in raise_if_nothing_inferred
    yield from generator
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/justkidding/git/astroid/astroid/inference.py", line 289, in infer_attribute
    for owner in self.expr.infer(context):
  File "/home/justkidding/git/astroid/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/justkidding/git/astroid/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 141, in raise_if_nothing_inferred
    yield from generator
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/justkidding/git/astroid/astroid/bases.py", line 132, in _infer_stmts
    for inferred in stmt.infer(context=context):
  File "/home/justkidding/git/astroid/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/justkidding/git/astroid/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 131, in raise_if_nothing_inferred
    yield next(generator)
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/justkidding/git/astroid/astroid/bases.py", line 132, in _infer_stmts
    for inferred in stmt.infer(context=context):
  File "/home/justkidding/git/astroid/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/justkidding/git/astroid/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 131, in raise_if_nothing_inferred
    yield next(generator)
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/justkidding/git/astroid/astroid/inference.py", line 223, in infer_call
    for callee in self.func.infer(context):
  File "/home/justkidding/git/astroid/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/justkidding/git/astroid/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 131, in raise_if_nothing_inferred
    yield next(generator)
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/justkidding/git/astroid/astroid/inference.py", line 289, in infer_attribute
    for owner in self.expr.infer(context):
  File "/home/justkidding/git/astroid/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/justkidding/git/astroid/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 131, in raise_if_nothing_inferred
    yield next(generator)
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 95, in wrapped
    res = next(generator)
  File "/home/justkidding/git/astroid/astroid/bases.py", line 132, in _infer_stmts
    for inferred in stmt.infer(context=context):
  File "/home/justkidding/git/astroid/astroid/util.py", line 160, in limit_inference
    yield from islice(iterator, size)
  File "/home/justkidding/git/astroid/astroid/context.py", line 113, in cache_generator
    for result in generator:
  File "/home/justkidding/git/astroid/astroid/decorators.py", line 131, in raise_if_nothing_inferred
    yield next(generator)
RuntimeError: generator raised StopIteration

Expected behavior

No stacktrace.

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

2.4.0 (git master), but also 2.3.X

[JustKiddingCode]

I was able to reduce the problem:
The interessting part is, that unpacking works when its not a dictionary! so first assigning to a variable works. Adding more information into the dictionary doesn't change something as well as
reducing the amount of variables of the dataclass.

from dataclasses import dataclass, replace

@dataclass
class ProxyConfig:
    """ Configuration for the Proxy Setup """
    auth: str = "/auth"


a = ProxyConfig("")
test_dict = {"proxy" : {"auth" : "", "bla" : "f"}}

foo = test_dict['proxy']
a = replace(a, **foo) # This works!
a = replace(a, **test_dict['proxy']) # This fails