Crash with --enable-incomplete-feature=Unpack and sliced numpy arrays.

[gatoniel]

Crash Report
I get an INTERNAL ERROR when I use --enable-incomplete-feature=Unpack with the code described below.

Traceback

mypy_unpack.py:47: 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: 1.6.0+dev.76c16a484b8b4fa6ae10abf4e96a286315ed7093
Traceback (most recent call last):
  File "/home/niklas/.pyenv/versions/mypy/bin/mypy", line 8, in <module>
    sys.exit(console_entry())
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/__main__.py", line 15, in console_entry
    main()
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/main.py", line 99, in main
    res, messages, blockers = run_build(sources, options, fscache, t0, stdout, stderr)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/main.py", line 178, in run_build
    res = build.build(sources, options, None, flush_errors, fscache, stdout, stderr)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/build.py", line 189, in build
    result = _build(
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/build.py", line 262, in _build
    graph = dispatch(sources, manager, stdout)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/build.py", line 2938, in dispatch
    process_graph(graph, manager)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/build.py", line 3336, in process_graph
    process_stale_scc(graph, scc, manager)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/build.py", line 3437, in process_stale_scc
    graph[id].type_check_first_pass()
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/build.py", line 2306, in type_check_first_pass
    self.type_checker().check_first_pass()
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 475, in check_first_pass
    self.accept(d)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 585, in accept
    stmt.accept(self)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/nodes.py", line 790, in accept
    return visitor.visit_func_def(self)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 972, in visit_func_def
    self._visit_func_def(defn)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 976, in _visit_func_def
    self.check_func_item(defn, name=defn.name)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 1049, in check_func_item
    self.check_func_def(defn, typ, name, allow_empty)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 1259, in check_func_def
    self.accept(item.body)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 585, in accept
    stmt.accept(self)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/nodes.py", line 1226, in accept
    return visitor.visit_block(self)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 2732, in visit_block
    self.accept(s)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 585, in accept
    stmt.accept(self)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/nodes.py", line 1313, in accept
    return visitor.visit_assignment_stmt(self)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 2780, in visit_assignment_stmt
    self.check_assignment(s.lvalues[-1], s.rvalue, s.type is None, s.new_syntax)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 2987, in check_assignment
    rvalue_type = self.expr_checker.accept(rvalue, type_context=type_context)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 5269, in accept
    typ = node.accept(self)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/nodes.py", line 1907, in accept
    return visitor.visit_call_expr(self)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 452, in visit_call_expr
    return self.visit_call_expr_inner(e, allow_none_return=allow_none_return)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 581, in visit_call_expr_inner
    ret_type = self.check_call_expr_with_callee_type(
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 1371, in check_call_expr_with_callee_type
    ret_type, callee_type = self.check_call(
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 1454, in check_call
    return self.check_callable_call(
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 1617, in check_callable_call
    callee = self.infer_function_type_arguments(
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 1925, in infer_function_type_arguments
    arg_types = self.infer_arg_types_in_context(
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 1814, in infer_arg_types_in_context
    res[ai] = self.accept(args[ai], arg_type)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 5269, in accept
    typ = node.accept(self)
          ^^^^^^^^^^^^^^^^^
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/nodes.py", line 2316, in accept
    return visitor.visit_generator_expr(self)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 5036, in visit_generator_expr
    return self.check_generator_or_comprehension(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 5050, in check_generator_or_comprehension
    self.check_for_comp(gen)
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checkexpr.py", line 5122, in check_for_comp
    _, sequence_type = self.chk.analyze_iterable_item_type(sequence)
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/checker.py", line 4648, in analyze_iterable_item_type
    joined = join_types(joined, item)
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/join.py", line 252, in join_types
    return t.accept(TypeJoinVisitor(s, instance_joiner))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/types.py", line 1058, in accept
    return visitor.visit_unpack_type(self)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/niklas/.pyenv/versions/3.11.1/envs/mypy/lib/python3.11/site-packages/mypy/join.py", line 315, in visit_unpack_type
    raise NotImplementedError
NotImplementedError:
mypy_unpack.py:47: : note: use --pdb to drop into pdb

To Reproduce

I ran mypy --enable-incomplete-feature=Unpack mypy_unpack.py --show-traceback with the following code:

# mypy_unpack.py
from __future__ import annotations

from typing import TypeVar
from typing import Any
from typing import Unpack

import numpy as np
import numpy.typing as npt


T = TypeVar("T", bound=np.generic)
U = TypeVar("U", bound=np.unsignedinteger[Any])


def sample_patches(
    datas: tuple[npt.NDArray[U], Unpack[tuple[npt.NDArray[T], ...]]],
    patch_size: tuple[int, ...],
    n_samples: int,
    valid_inds: tuple[npt.NDArray[np.uint32], ...] | None = None,
    verbose: bool = False,
) -> tuple[npt.NDArray[U], Unpack[tuple[npt.NDArray[T], ...]]]:
    """Version of stardist.sample_patches.sample_patches for time stacks."""

    if valid_inds is None:
        valid_inds = tuple(
            _s.ravel()
            for _s in np.meshgrid(
                *tuple(
                    np.arange(p // 2, s - p // 2 + 1)
                    for s, p in zip(datas[0].shape[1:], patch_size)
                )
            )
        )

    n_valid = len(valid_inds[0])

    if n_valid == 0:
        raise ValueError("no regions to sample from!")

    idx = list(
        np.random.choice(
            range(n_valid), n_samples, replace=(n_valid < n_samples)
        )
    )
    rand_inds = [v[idx] for v in valid_inds]
    res = tuple(
        np.stack(
            [
                data[
                    (slice(None),)
                    + tuple(
                        slice(_r - (_p // 2), _r + _p - (_p // 2))
                        for _r, _p in zip(r, patch_size)
                    )
                ]
                for r in zip(*rand_inds)
            ]
        )
        for data in datas
    )

    return res

Your Environment

• Mypy version used: 1.6.0+dev.76c16a484b8b4fa6ae10abf4e96a286315ed7093
• Mypy command-line flags: --enable-incomplete-feature=Unpack
• Mypy configuration options from mypy.ini (and other config files): plugins = "numpy.typing.mypy_plugin" is part of [tool.mypy] in the pyproject.toml.
• Python version used: 3.11.1
• Operating system and version: Ubuntu 22.04.1 LTS