DefaultDict of a TypedDict confuses mypy

Hi 👋 ! I have the following test code:

from collections import defaultdict

from typing import DefaultDict
from mypy_extensions import TypedDict

RepoPath = str
RepoStatus = TypedDict('RepoStatus', {
    'branch': str,
    'remote': str,
    'clean': bool,
    # ...
}, total=False)

State2 = defaultdict(RepoStatus)            # type: DefaultDict[RepoPath, RepoStatus]
State3 = defaultdict(dict)                  # type: DefaultDict[RepoPath, RepoStatus]
State4 = defaultdict(lambda: RepoStatus())  # type: DefaultDict[RepoPath, RepoStatus]
State5 = defaultdict(lambda: dict())        # type: DefaultDict[RepoPath, RepoStatus]
State6 = defaultdict(lambda: {})            # type: DefaultDict[RepoPath, RepoStatus]

mypy only accepts the definition of 4 and 6. A pic is easy to follow here

mypy output:

 16:10  error  mypy  Argument 1 to "defaultdict" has incompatible type "Type[RepoStatus]"; expected
                     "Optional[Callable[[], RepoStatus]]"
 17:10  error  mypy  Argument 1 to "defaultdict" has incompatible type "Type[Dict[Any, Any]]";
                     expected "Optional[Callable[[], RepoStatus]]"
 19:10  error  mypy  Argument 1 to "defaultdict" has incompatible type "Callable[[], Dict[<nothing>,
                     <nothing>]]"; expected "Optional[Callable[[], RepoStatus]]"
 19:22  error  mypy  Incompatible return value type (got "Dict[<nothing>, <nothing>]", expected
                     "RepoStatus")

Ideally the def of State3, just defaultdict(dict), should work, shouldn't it? It is also very surprising that there is a difference between 5 and 6.

mypy 0.720

Start by reproducing the issue's State2–State6 snippet with mypy 0.720 and compare the diagnostics for each defaultdict form. Trace how defaultdict constructor arguments and TypedDict return types are inferred; done means the intended forms type-check consistently and the unexpected difference between State5 and State6 is resolved or documented by tests.