Internal error with nested `Unpack` and `@overload`

[jorenham]

Describe the problem, ie expected/actual result (if it's not blatantly obvious)

The relevant code:

https://github.com/jorenham/scipy-stubs/blob/master/scipy-stubs/stats/_distn_infrastructure.pyi#L197-L233

When I run mypy --show-traceback scipy-stubs/stats/_distn_infrastructure.pyi:

scipy-stubs/stats/_distn_infrastructure.pyi:197: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://kotlinisland.github.io/basedmypy/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/KotlinIsland/basedmypy/issues
version: 2.7.0+dev.4c2c2e5000d53f89d59fa0b208be793b71e9c2fe
Traceback (most recent call last):
  File "/dev/scipy-stubs/.venv/bin/mypy", line 8, in <module>
    sys.exit(console_entry())
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/__main__.py", line 15, in console_entry
    main()
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/main.py", line 108, in main
    res, messages, blockers = run_build(sources, options, fscache, t0, stdout, stderr)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/main.py", line 217, in run_build
    res = build.build(sources, options, None, flush_errors, fscache, stdout, stderr)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/build.py", line 198, in build
    result = _build(
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/build.py", line 276, in _build
    graph = dispatch(sources, manager, stdout)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/build.py", line 3092, in dispatch
    process_graph(graph, manager)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/build.py", line 3492, in process_graph
    process_stale_scc(graph, scc, manager)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/build.py", line 3593, in process_stale_scc
    graph[id].type_check_first_pass()
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/build.py", line 2455, in type_check_first_pass
    self.type_checker().check_first_pass()
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 505, in check_first_pass
    self.accept(d)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 613, in accept
    stmt.accept(self)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/nodes.py", line 1187, in accept
    return visitor.visit_class_def(self)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 2650, in visit_class_def
    self.accept(defn.defs)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 613, in accept
    stmt.accept(self)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/nodes.py", line 1268, in accept
    return visitor.visit_block(self)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 3116, in visit_block
    self.accept(s)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 613, in accept
    stmt.accept(self)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/nodes.py", line 591, in accept
    return visitor.visit_overloaded_func_def(self)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 650, in visit_overloaded_func_def
    self._visit_overloaded_func_def(defn, do_items)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 681, in _visit_overloaded_func_def
    self.check_overlapping_overloads(defn)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 814, in check_overlapping_overloads
    if is_unsafe_overlapping_overload_signatures(sig1, sig2, type_vars):
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 8549, in is_unsafe_overlapping_overload_signatures
    is_callable_compatible(
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/subtypes.py", line 1623, in is_callable_compatible
    return are_parameters_compatible(
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/subtypes.py", line 1730, in are_parameters_compatible
    if _incompatible(left_star, right_star) or _incompatible(left_star2, right_star2):
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/subtypes.py", line 1728, in _incompatible
    return not is_compat(right_arg.typ, left_arg.typ)
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/checker.py", line 9083, in is_overlapping_types_for_overload
    return is_overlapping_types(
  File "/dev/scipy-stubs/.venv/lib/python3.10/site-packages/mypy/meet.py", line 619, in is_overlapping_types
    assert type(left) != type(right), f"{type(left)} vs {type(right)}"
AssertionError: <class 'mypy.types.UnpackType'> vs <class 'mypy.types.UnpackType'>
scipy-stubs/stats/_distn_infrastructure.pyi:197: : note: use --pdb to drop into pdb

so here I am 🤷🏻

---

(yes, I'm actually stubbing scipy 🙃)

Gist to reproduce

https://github.com/jorenham/scipy-stubs/blob/master/scipy-stubs/stats/_distn_infrastructure.pyi#L197-L233

Basedmypy version

basedmypy 2.7.0+dev.4c2c2e5000d53f89d59fa0b208be793b71e9c2fe (compiled: no)
Based on mypy 1.11.0+dev

Command-line flags

No response

Configuration options from pyproject.toml (and other config files)

disable_bytearray_promotion=true; disable_memoryview_promotion=true; disallow_any_explicit=false; warn_unuseda_ignores=true

Python version used

three dot ten dot twelve

Operating system and version

PopOS! / Ubuntu 22.04 (won't recommend)

[KotlinIsland]

looks like it's also affecting upstream, here's a minified example:

from typing import overload

from typing_extensions import Unpack


class A:
    @overload
    def f(self, *args: Unpack[tuple[Unpack[tuple[str, ...]]]]) -> int: ...
    @overload
    def f(self): ...

playground

[KotlinIsland]

btw, i would recomment uv (+ pyprojectx) over poetry

i think it would be a good idea to add this project to the [based]mypy primer

additionally, i would like to keep an open dialogue with you about any changes that would be introduced into basedmypy since you are using it, do you have discord or something?

[jorenham]

@KotlinIsland sure, is telegram ok?

[jorenham]

@KotlinIsland the most nerdy anti-scraper measure I could think of:

f"+{0x75e67144a}"

[KotlinIsland]

my telegram is: @KotlinIslandsTaken