INTERNAL ERROR -- Please try using mypy master on GitHub

[ClasherKasten]

Crash Report

When running mypy in one of the projects I work on, it gives this error

Traceback

src/AthenaCSS/models/css/at_rules.py:141: 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: 0.982
Traceback (most recent call last):
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/bin/mypy", line 8, in <module>
    sys.exit(console_entry())
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/__main__.py", line 15, in console_entry
    main()
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/main.py", line 95, in main
    res, messages, blockers = run_build(sources, options, fscache, t0, stdout, stderr)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/main.py", line 174, in run_build
    res = build.build(sources, options, None, flush_errors, fscache, stdout, stderr)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/build.py", line 187, in build
    result = _build(
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/build.py", line 270, in _build
    graph = dispatch(sources, manager, stdout)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/build.py", line 2867, in dispatch
    process_graph(graph, manager)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/build.py", line 3251, in process_graph
    process_stale_scc(graph, scc, manager)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/build.py", line 3352, in process_stale_scc
    graph[id].type_check_first_pass()
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/build.py", line 2295, in type_check_first_pass
    self.type_checker().check_first_pass()
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 467, in check_first_pass
    self.accept(d)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 575, in accept
    stmt.accept(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/nodes.py", line 1127, in accept
    return visitor.visit_class_def(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 2026, in visit_class_def
    self.accept(defn.defs)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 575, in accept
    stmt.accept(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/nodes.py", line 1202, in accept
    return visitor.visit_block(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 2406, in visit_block
    self.accept(s)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 575, in accept
    stmt.accept(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/nodes.py", line 618, in accept
    return visitor.visit_overloaded_func_def(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 612, in visit_overloaded_func_def
    self._visit_overloaded_func_def(defn)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 628, in _visit_overloaded_func_def
    self.check_func_item(fdef.func, name=fdef.func.name)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 1010, in check_func_item
    self.check_func_def(defn, typ, name)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 1194, in check_func_def
    self.accept(item.body)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 575, in accept
    stmt.accept(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/nodes.py", line 1202, in accept
    return visitor.visit_block(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 2406, in visit_block
    self.accept(s)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 575, in accept
    stmt.accept(self)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/nodes.py", line 1555, in accept
    return visitor.visit_match_stmt(self)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 4462, in visit_match_stmt
    pattern_types = [self.pattern_checker.accept(p, subject_type) for p in s.patterns]
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checker.py", line 4462, in <listcomp>
    pattern_types = [self.pattern_checker.accept(p, subject_type) for p in s.patterns]
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checkpattern.py", line 119, in accept
    result = o.accept(self)
             ^^^^^^^^^^^^^^
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/patterns.py", line 93, in accept
    return visitor.visit_sequence_pattern(self)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checkpattern.py", line 307, in visit_sequence_pattern
    new_type = self.construct_sequence_child(current_type, new_inner_type)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checkpattern.py", line 651, in construct_sequence_child
    types = [
            ^
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checkpattern.py", line 652, in <listcomp>
    self.construct_sequence_child(item, inner_type)
  File "/home/clasherkasten/Dokumente/Python/athena-workspace/workspace/ClasherKasten/AthenaCSS/venv/lib/python3.11/site-packages/mypy/checkpattern.py", line 660, in construct_sequence_child
    assert isinstance(proper_type, Instance)
AssertionError: 
src/AthenaCSS/models/css/at_rules.py:141: : note: use --pdb to drop into pdb

To Reproduce

copy into a file:

from __future__ import annotations

from typing import TypeAlias


TNegative: TypeAlias = str | tuple[str, str] | None


class CounterStyle:
    def __init__(self, negative: TNegative) -> None:
        self.negative = negative

    @property
    def negative(self) -> str:
        return self._negative

    @negative.setter
    def negative(self, new_negative: TNegative) -> None:
        match new_negative:
            case str(s):
                self._negative = f'negative: "{s}";'
            case (str(s1), str(s2)):
                self._negative = f'negative: "{s1}" "{s2}";'
            case None:
                self._negative = ''
            case _:
                raise Exception('Error msg...')

and run mypy <that-file>

Your Environment

• Mypy version used: mypy 0.982 (compiled: no)
• Mypy command-line flags:
• Mypy configuration options from .mypy.ini:

[mypy]
check_untyped_defs = true
disallow_any_generics = true
disallow_incomplete_defs = true
disallow_untyped_defs = true
enable_recursive_aliases = true
no_implicit_optional = true
warn_redundant_casts = true
warn_unused_ignores = true

• Python version used: 3.11.0
• Operating system and version: Kubuntu 22.04

[AlexWaygood]

Simpler repro:

new_negative: str | tuple[str, str]

match new_negative:
    case (str(s1), str(s2)):
        y = f'negative: "{s1}" "{s2}";'

https://mypy-play.net/?mypy=latest&python=3.10&flags=show-traceback&gist=8fc7f5f95cf976a9f391613147119500

[AlexWaygood]

Duplicate of #12533; this should already be fixed on mypy master.

[AlexWaygood]

I confirmed locally that the crash can be reproduced on mypy 0.982, but not on mypy master (it was fixed in #13514). The fix will be released as part of mypy 0.990 (follow #13871 for progress updates).