Crash on unpacked tuple in tuple type definition

[dzsaska]

Crash Report
Mypy 1.20.2 is crashing when processing type definition of a tuple that unpacks another tuple. I have a reproducer on mypy-play with latest version (2.3.1). See https://mypy-play.net/?gist=43e256f314819d34c14f92b9098ed40c

Traceback

mre.py:12: 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: 1.20.2
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "mypy/checkexpr.py", line 6092, in accept
  File "mypy/checkexpr.py", line 6127, in accept_maybe_cache
  File "mypy/nodes.py", line 2469, in accept
  File "mypy/checkexpr.py", line 502, in visit_call_expr
  File "mypy/checkexpr.py", line 639, in visit_call_expr_inner
  File "mypy/checkexpr.py", line 1489, in check_call_expr_with_callee_type
  File "mypy/checkexpr.py", line 1593, in check_call
  File "mypy/checkexpr.py", line 2749, in check_overload_call
  File "mypy/checkexpr.py", line 2917, in infer_overload_return_type
  File "mypy/checkexpr.py", line 1582, in check_call
  File "mypy/checkexpr.py", line 1747, in check_callable_call
  File "mypy/checkexpr.py", line 2060, in infer_function_type_arguments_using_context
  File "mypy/checkexpr.py", line 3292, in apply_generic_arguments
  File "mypy/applytype.py", line 115, in apply_generic_arguments
  File "mypy/applytype.py", line 79, in get_target_type
  File "mypy/subtypes.py", line 189, in is_subtype
  File "mypy/subtypes.py", line 363, in _is_subtype
  File "mypy/types.py", line 2818, in accept
  File "mypy/subtypes.py", line 798, in visit_tuple_type
  File "mypy/typeops.py", line 119, in tuple_fallback
NotImplementedError: 
mre.py:12: note: use --pdb to drop into pdb

To Reproduce
See https://mypy-play.net/?gist=43e256f314819d34c14f92b9098ed40c

"""
Minimal reproducer: mypy 1.20.2 (and latest 2.3.1) crashes on a nested tuple type alias unpack.
"""

from collections import deque

type Inner = tuple[int, str]
type Outer = tuple[bool, *Inner]


class K(Base):
    q: deque[Outer] = deque()


class Base: ...

Your Environment

• Mypy version used: 1.20.2 and 2.3.1
• Mypy command-line flags: python -m mypy --python-version 3.12 --no-incremental --cache-dir=/dev/null --show-traceback mre.py
• Python version used: Python 3.12.13

[EmmanuelNiyonshuti]

Is that expected to work? class Base is being used before it is defined. Although, I don't think mypy should crash here.

On that note, I also hit the same crash when using Base in an annotation:

from __future__ import annotations

from collections import deque

type Inner = tuple[int, str]
type Outer = tuple[bool, *Inner]

class K:
    x: Base
    q: deque[Outer] = deque()

class Base: ...