Crash with variadic type variable

Tái hiện test.py được cung cấp bằng mypy --show-traceback, sau đó lần theo đường đi của lỗi từ checker.py:check_with_item qua checkexpr.py:visit_call_expr và visit_call_expr_inner. Traceback và báo cáo xác định đường đi của sự cố; hoàn tất khi ví dụ kiểu variadic này không còn tạo ra INTERNAL ERROR hoặc traceback.

Crash Report

I was writing some code in Colab and INTERNAL_ERROR showed up

This is the code:
%%mypy
from collections.abc import Callable, Mapping, MutableMapping, Iterator, Iterable
from typing import Any, Self, NoReturn, Concatenate, overload, TYPE_CHECKING, cast, TypeVar, final, Literal, Protocol
from typing_extensions import disjoint_base, TypeForm
from functools import wraps
from types import MethodType as method, TracebackType
import sys

@disjoint_base
class cached[**P, R]:
slots = ("_f", "_c")
def init(self, func: Callable[P, R]) -> None:
if not hasattr(self, "_f"):
self._f = func
self._c = {} # type: ignore[var-annotated]

@property
def cache(self) -> dict[tuple[tuple, frozenset[tuple[str, Any]]], R]:
return self._c

def call(self, *args: P.args, **kwargs: P.kwargs) -> R:
compd = (args, frozenset(kwargs.items()))
if compd in self._c:
return self._c[compd]

else:
  result = self._f(*args, **kwargs)
  self._c[compd] = result
  return result

def repr(self) -> str:
return self._f.name

@disjoint_base
class cached_method[T, **P, R]:
slots = ("_f", "_c")
def init(self, func: Callable[Concatenate[T, P], R]) -> None:
if not hasattr(self, "_f"):
self._f = func
self._c = {} # type: ignore[var-annotated]

@property
def cache(self) -> dict[tuple[T, tuple[Any, ...], frozenset[tuple[str, Any]]], R]:
return self._c

def call(self, instance: T, /, *args: P.args, **kwargs: P.kwargs) -> R:
compd = (instance, args, frozenset(kwargs.items()))
if compd in self._c:
return self._c[compd]

else:
  result = self._f(instance, *args, **kwargs)
  self._c[compd] = result
  return result

def repr(self) -> str:
return self._f.name

@overload
def get(self, instance: None, owner: type[T]) -> Self: ...
@overload
def get(self, instance: T, owner: type[T]) -> cached: ...
def get(self, instance: T | None, owner: type[T]):
@cached
def _cached_method_get(self, instance, owner):
if instance is None:
return self

  else:
    return cached(method(self._f, instance))

return _cached_method_get(self, instance, owner)

def notimplemented[**P](func: Callable[P, Any]) -> Callable[P, NoReturn]:
@wraps(func)
def wrapper(*args: P.args, **kwargs: P.kwargs) -> NoReturn:
raise NotImplementedError

return wrapper

type _BinaryMethod[T, N] = Callable[[T, N], bool]
def typeguard[T](cls: type[T]) -> Callable[[_BinaryMethod[T, T]], BinaryMethod[T, object]]:
def dec(method: _BinaryMethod[T, T]) -> BinaryMethod[T, object]:
@wraps(method)
def wrapper(self_param, other: object) -> bool:
if not isinstance(other, cls):
return NotImplemented

  else:
    return method_(self_param, other)

return wrapper

return dec

@disjoint_base
class immutabledict[K, V]:
slots = ("_data",)
_data: dict[K, V]

def new(cls, dict_: Mapping[K, V] = {}, /) -> Self:
self = object.new(cls)
self.data = dict(dict)
return self

@property
def data(self, /) -> dict[K, V]:
return self._data

def contains(self, item: object) -> bool:
return self._data.contains(item)

def eq(self, other: object, /) -> bool:
@typeguard(immutabledict)
def wrapper(self_param, other: immutabledict, /) -> bool:
return self_param._data == other._data

return wrapper(self, other)

def getitem(self, item: K, /) -> V:
return self._data.getitem(item)

def hash(self, /) -> int:
return hash((frozenset(self._data.items()), 23*len(self), type)) ^ 2**20

def iter(self, /) -> Iterator[K]:
return iter(self._data)

def len(self, /) -> int:
return self._data.len()

def or(self, other: "immutabledict", /) -> Self:
return type(self)(self._data.or(other._data))

def reduce(self, /) -> tuple[type[Self], tuple[dict[K, V]]]:
return (type(self), (self._data,))

def repr(self, /) -> str:
return f"{type(self).name}({self._data!r})"

def reversed(self, /) -> Iterator[K]:
return self._data.reversed()

ror = or

def str(self) -> str:
return f"{type(self).name}({self._data})"

def copy(self, /) -> Self:
return self

@classmethod
def fromkeys(cls, iterable: Iterable[K], value: V, /) -> Self:
return cls(dict.fromkeys(iterable, value))

def get[_T](self, key: K, default: _T) -> V | _T:
if key in self._data:
return self._data.getitem(key)

else:
  return default

def items(self, /) -> "immutabledict_items[K, V]":
return immutabledict_items(frozenset(self._data.items()))

def keys(self, /) -> "immutabledict_keys[K]":
return immutabledict_keys(frozenset(self._data.keys()))

def values(self, /) -> "immutabledict_values[V]":
return immutabledict_values(frozenset(self._data.values()))

@disjoint_base
class _immutabledict_view[T]:
slots = ("_data",)
_data: frozenset[T]

def new(cls, fset: frozenset[T], /) -> Self:
self = object.new(cls)
self._data = fset
return self

@property
def data(self) -> frozenset[T]:
return self._data

def and(self, other: Iterable, /) -> frozenset[T]:
return self._data & frozenset(other)

def contains(self, item: object, /):
return self._data.contains(item)

def eq(self, other: object, /) -> bool:
if isinstance(other, _immutabledict_view):
return self._data == other._data

else:
  return NotImplemented

def hash(self, /) -> int:
return hash((frozenset(self._data), 34, len(self), object)) ^ 2**20

def len(self, /) -> int:
return self._data.len()

def iter(self, /) -> Iterator[T]:
return self._data.iter()

def or[_T](self, other: Iterable[_T], /) -> frozenset[T | _T]:
return self._data.or(frozenset(other))

rand = and

def repr(self) -> str:
return f"{type(self).name}({self._data!r})"

def rsub(self, other: Iterable, /) -> frozenset[T]:
return self._data.sub(frozenset(other))

def rxor[_T](self, other: Iterable[_T], /) -> frozenset[T | _T]:
return self._data.xor(frozenset(other))

ror = or
sub = rsub
xor = rxor

class immutabledict_items[K, V](_immutabledict_view[tuple[K, V]]):
pass

class immutabledict_keysK:
pass

class immutabledict_valuesV:
pass

class _exitE: BaseException, R:
@overload
def call(self, exc_tp: type[BaseException], exc: BaseException, tb: TracebackType, result: R, /) -> bool: ...

@overload
def call(self, exc_tp: None, exc: None, tb: None, result: R, /) -> bool: ...

@final
class contextmanager[**P, R]:
slots = ("_func", "exit")
_func: Callable[P, R]
exit: _exit[BaseException, R]

def new(cls, func: Callable[P, R]) -> Self:
self = object.new(cls)
self._func = func

def _exit_inner(
    exc_tp: type[BaseException] | None,
    exc: BaseException | None,
    tb: TracebackType | None,
    result: R,
    /
) -> bool:
  return False

self._exit_ = _exit_inner
return self

def call(self, *args: P.args, **kwargs: P.kwargs) -> "_contextmanager_cls[P, R]":
return _contextmanager_cls(self.exit, self._func(*args, **kwargs))

def exit(self, func: _exit[BaseException, R]) -> Self:
self.exit = func
return self

class _contextmanager_cls[**P, R]:
slots = ("_value", "exit")
_value: R
exit: _exit[BaseException, R]

def new(cls, exit: _exit[BaseException, R], value: R) -> Self:
self = object.new(cls)
self._value = value
self.exit = exit
return self

def enter(self) -> R:
return self._value

def exit(self, exc_tp: type[BaseException], exc: BaseException, tb: TracebackType) -> bool:
return self.exit(exc_tp, exc, tb, self._value)

Float = TypeVar("Float", int, float)
Complex = TypeVar("Complex", int, float, complex)

@contextmanager
def print_args[*Ts](*args: *Ts) -> tuple[*Ts]:
print("Function called with:", *args)
return args

@print_args.exit
def _(exc_tp, exc, tb, result):
if exc is not None:
print(f"Exception suppressed: {exc_tp.name}({exc})")
return True

with print_args(2) as n:
print(n, "in with block")
raise ValueError("hi")

Traceback

test.py:301: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 2.4.0+dev.722047e369657c936851a349ebba6b4c5504b8e2
Traceback (most recent call last):
File "/usr/local/bin/mypy", line 8, in
sys.exit(console_entry())
File "/usr/local/lib/python3.12/dist-packages/mypy/main.py", line 16, in console_entry
main()
File "/usr/local/lib/python3.12/dist-packages/mypy/main.py", line 154, in main
res, messages, blockers = run_build(sources, options, fscache, t0, stdout, stderr)
File "/usr/local/lib/python3.12/dist-packages/mypy/main.py", line 244, in run_build
res = build.build(sources, options, None, flush_errors, fscache, stdout, stderr)
File "/usr/local/lib/python3.12/dist-packages/mypy/build.py", line 422, in build
result = build_inner(
File "/usr/local/lib/python3.12/dist-packages/mypy/build.py", line 537, in build_inner
graph = dispatch(sources, manager, stdout, connect_threads)
File "/usr/local/lib/python3.12/dist-packages/mypy/build.py", line 4150, in dispatch
process_graph(graph, manager)
File "/usr/local/lib/python3.12/dist-packages/mypy/build.py", line 4618, in process_graph
done, still_working, results = manager.wait_for_done(graph)
File "/usr/local/lib/python3.12/dist-packages/mypy/build.py", line 1484, in wait_for_done
process_stale_scc(graph, next_scc, self)
File "/usr/local/lib/python3.12/dist-packages/mypy/build.py", line 4793, in process_stale_scc
graph[id].type_check_first_pass()
File "/usr/local/lib/python3.12/dist-packages/mypy/build.py", line 3410, in type_check_first_pass
self.type_checker().check_first_pass(recurse_into_functions=recurse_into_functions)
File "/usr/local/lib/python3.12/dist-packages/mypy/checker.py", line 618, in check_first_pass
self.accept(d)
File "/usr/local/lib/python3.12/dist-packages/mypy/checker.py", line 765, in accept
stmt.accept(self)
File "/usr/local/lib/python3.12/dist-packages/mypy/nodes.py", line 2185, in accept
return visitor.visit_with_stmt(self)
File "/usr/local/lib/python3.12/dist-packages/mypy/checker.py", line 5902, in visit_with_stmt
exit_ret_type = self.check_with_item(expr, target, s.unanalyzed_type is None)
File "/usr/local/lib/python3.12/dist-packages/mypy/checker.py", line 5963, in check_with_item
ctx = echk.accept(expr)
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 6220, in accept
typ = self.accept_maybe_cache(node, type_context=type_context)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 6255, in accept_maybe_cache
typ = node.accept(self)
^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/nodes.py", line 2545, in accept
return visitor.visit_call_expr(self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 499, in visit_call_expr
return self.visit_call_expr_inner(e, allow_none_return=allow_none_return)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 630, in visit_call_expr_inner
ret_type = self.check_call_expr_with_callee_type(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 1498, in check_call_expr_with_callee_type
ret_type, callee_type = self.check_call(
^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 1626, in check_call
result = self.check_call(
^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 1591, in check_call
return self.check_callable_call(
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 1793, in check_callable_call
callee = self.infer_function_type_arguments(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 2286, in infer_function_type_arguments
return self.apply_inferred_arguments(callee_type, inferred_args, context)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 2421, in apply_inferred_arguments
return self.apply_generic_arguments(callee_type, inferred_args, context)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/checkexpr.py", line 3424, in apply_generic_arguments
return applytype.apply_generic_arguments(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/applytype.py", line 147, in apply_generic_arguments
callable = expand_type(callable, id_to_type)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/expandtype.py", line 70, in expand_type
return typ.accept(ExpandTypeVisitor(env))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/types.py", line 2361, in accept
return visitor.visit_callable_type(self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/expandtype.py", line 495, in visit_callable_type
ret_type=t.ret_type.accept(self),
^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/types.py", line 1684, in accept
return visitor.visit_instance(self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/expandtype.py", line 217, in visit_instance
args = self.expand_type_tuple_with_unpack(t.args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/expandtype.py", line 531, in expand_type_tuple_with_unpack
items.append(item.accept(self))
^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/types.py", line 2073, in accept
return visitor.visit_parameters(self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/expandtype.py", line 403, in visit_parameters
return t.copy_modified(arg_types=self.expand_types(t.arg_types))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/expandtype.py", line 616, in expand_types
a.append(t.accept(self))
^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/types.py", line 1248, in accept
return visitor.visit_unpack_type(self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/expandtype.py", line 380, in visit_unpack_type
return UnpackType(t.type.accept(self))
^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/types.py", line 1007, in accept
return visitor.visit_type_var_tuple(self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/dist-packages/mypy/expandtype.py", line 368, in visit_type_var_tuple
raise NotImplementedError
NotImplementedError

test.py:301: note: use --pdb to drop into pdb

To Reproduce

Setup:
!pip install git+https://github.com/python/mypy.git
from IPython.core.magic import register_cell_magic
from IPython import get_ipython
from mypy import api

@register_cell_magic
def mypy(line, cell):

mypy.api.run returns (stdout, stderr, exit_code)

stdout, stderr, exit_code = api.run(['-c', '\n' + cell] + line.split())

if stderr:
# If there's anything in stderr, it's usually an internal mypy error or argument error
raise TypeError(f"Mypy stderr:\n{stderr}")

if exit_code != 0:
# Mypy found type errors or exited with a non-zero status
if stdout:
raise TypeError(f"Mypy type errors:\n{stdout}")
else:
raise TypeError(f"Mypy exited with code {exit_code} but no output.")

If exit_code is 0 and no stderr, mypy passed, then run the cell

get_ipython().run_cell(cell)

Your Environment

Google colab, python 3.12