Fix bad-specialization false positive for bounded TypeVar in callable (#1960) #1974

jackulau · 2025-12-31T20:41:44Z

Summary

Fixes #1960

When passing a generic class as a factory to a function expecting Callable[[T], Result[T]], pyrefly incorrectly reported a bad-specialization error

The Problem

from collections.abc import Callable

class Box[U]:
    pass

class Result[T: int]:
    def __init__(self, x: T | Box[T]) -> None:
        pass

def f[T: int](factory: Callable[[T], Result[T]]) -> None:
    pass

f(factory=Result)  # ERROR: `Box[Unknown] | Unknown` is not assignable to upper bound `int`

Root Cause

When checking $T <: SomeType where $T has a bound (e.g., T: int), the solver was:

Setting $T = SomeType
Then checking if SomeType satisfies the bound

For this case, the constructor callable for Result[Any] has parameter type Any | Box[Any]. The solver set $T = Any | Box[Any] and then checked Any | Box[Any] <: int, which failed.

The Fix

Before setting the type variable, check if the bound already satisfies the constraint. If bound <: target, then any value within the bound automatically satisfies the constraint by transitivity, so we can return early without incorrectly setting the variable.

For this case: int <: Any | Box[Any] is true (since int <: Any), so the constraint is satisfied without needing to set $T = Any | Box[Any].

Test Plan

Added regression test test_callable_constructor_bounded_typevar_with_union_param

…facebook#1960)

github-actions · 2026-01-01T22:44:02Z

Diff from mypy_primer, showing the effect of this PR on open source code:

CPython (cases_generator) (https://github.com/python/cpython)
- ERROR Tools/cases_generator/parsing.py:333:5-16: Argument `(self: Self@Parser) -> Family | InstDef | LabelDef | Macro | Pseudo | None` is not assignable to parameter `func` with type `(Self@Parser) -> Family | None` in function `contextual` [bad-argument-type]
+ ERROR Tools/cases_generator/parsing.py:333:5-16: Argument `(self: Self@Parser) -> Family | InstDef | LabelDef | Macro | Pseudo | None` is not assignable to parameter `func` with type `(Parser) -> Family | None` in function `contextual` [bad-argument-type]
- ERROR Tools/cases_generator/parsing.py:429:5-16: Argument `(self: Self@Parser) -> CacheEffect | StackEffect | None` is not assignable to parameter `func` with type `(Self@Parser) -> CacheEffect | None` in function `contextual` [bad-argument-type]
+ ERROR Tools/cases_generator/parsing.py:429:5-16: Argument `(self: Self@Parser) -> CacheEffect | StackEffect | None` is not assignable to parameter `func` with type `(Parser) -> CacheEffect | None` in function `contextual` [bad-argument-type]
- ERROR Tools/cases_generator/parsing.py:535:5-16: Argument `(self: Self@Parser) -> CacheEffect | OpName | None` is not assignable to parameter `func` with type `(Self@Parser) -> CacheEffect | None` in function `contextual` [bad-argument-type]
+ ERROR Tools/cases_generator/parsing.py:535:5-16: Argument `(self: Self@Parser) -> CacheEffect | OpName | None` is not assignable to parameter `func` with type `(Parser) -> CacheEffect | None` in function `contextual` [bad-argument-type]

nionutils (https://github.com/nion-software/nionutils)
+ ERROR nion/utils/StructuredModel.py:158:29-45: Type `object` is not iterable [not-iterable]
+ ERROR nion/utils/StructuredModel.py:211:29-50: Type `object` is not iterable [not-iterable]
+ ERROR nion/utils/StructuredModel.py:281:42-53: Argument `object` is not assignable to parameter `schema` with type `dict[str, Any] | str` in function `build_value` [bad-argument-type]
+ ERROR nion/utils/StructuredModel.py:311:44-55: Argument `object` is not assignable to parameter `schema` with type `dict[str, Any] | str` in function `build_value` [bad-argument-type]

psycopg (https://github.com/psycopg/psycopg)
+ ERROR docs/lib/pg3_docs.py:68:30-34: Argument `bytes | str` is not assignable to parameter `prefix` with type `str | tuple[str, ...]` in function `str.startswith` [bad-argument-type]
+ ERROR psycopg_c/build_backend/psycopg_build_ext.py:56:56-69: `+` is not supported between `bytes` and `Literal['.pyx']` [unsupported-operation]
+ ERROR psycopg_c/build_backend/psycopg_build_ext.py:57:42-55: `+` is not supported between `bytes` and `Literal['.pyx']` [unsupported-operation]

svcs (https://github.com/hynek/svcs)
+ ERROR src/svcs/starlette.py:89:27-38: `dict[str, object] | object | Unknown` is not assignable to attribute `_state` with type `dict[str, object]` [bad-assignment]

egglog-python (https://github.com/egraphs-good/egglog-python)
+ ERROR python/egglog/egraph.py:2165:31-57: Argument `((egraph: EGraph, expr: BaseExpr, children_costs: list[int]) -> int) | CostModel[Any]` is not assignable to parameter `base` with type `CostModel[ComparableAddSub]` in function `GreedyDagCostModel.__init__` [bad-argument-type]

Tanjun (https://github.com/FasterSpeeding/Tanjun)
+ ERROR tanjun/_internal/__init__.py:568:32-43: `list[tuple[list[str], MessageCommand[Any]]] | object | Unknown` is not assignable to variable `node` with type `dict[_IndexKeys | str, list[tuple[list[str], MessageCommand[Any]]] | Unknown] | list[tuple[list[str], MessageCommand[Any]]]` [bad-assignment]

archinstall (https://github.com/archlinux/archinstall)
+ ERROR archinstall/lib/disk/device_handler.py:188:12-16: Returned type `object` is not assignable to declared return type `_PartitionInfo | None` [bad-return]
+ ERROR archinstall/lib/models/device.py:415:14-28: Object of class `object` has no attribute `value` [missing-attribute]
+ ERROR archinstall/lib/models/device.py:415:31-44: Object of class `object` has no attribute `unit` [missing-attribute]
+ ERROR archinstall/lib/models/device.py:416:13-27: Object of class `object` has no attribute `value` [missing-attribute]

cwltool (https://github.com/common-workflow-language/cwltool)
+ ERROR cwltool/builder.py:246:38-39: Cannot set item in `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None]` [unsupported-operation]
+ ERROR cwltool/builder.py:283:21-23: Argument `MutableMapping[str, object]` is not assignable to parameter `schema` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None]` in function `Builder.bind_input` [bad-argument-type]
+ ERROR cwltool/builder.py:292:25-27: Argument `MutableMapping[str, object]` is not assignable to parameter `schema` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None]` in function `Builder.bind_input` [bad-argument-type]
+ ERROR cwltool/builder.py:678:41-42: Argument `object` is not assignable to parameter `ex` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `Builder.do_eval` [bad-argument-type]
+ ERROR cwltool/builder.py:680:38-39: Argument `object` is not assignable to parameter `ex` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `Builder.do_eval` [bad-argument-type]
+ ERROR cwltool/checker.py:89:40-41: Argument `object` is not assignable to parameter `src` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `merge_flatten_type` [bad-argument-type]
+ ERROR cwltool/checker.py:134:47-55: Argument `object` is not assignable to parameter `src` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `can_assign_src_to_sink` [bad-argument-type]
+ ERROR cwltool/checker.py:138:62-70: Argument `object` is not assignable to parameter `src` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `can_assign_src_to_sink` [bad-argument-type]
+ ERROR cwltool/checker.py:143:44-53: Argument `object` is not assignable to parameter `sink` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `can_assign_src_to_sink` [bad-argument-type]
+ ERROR cwltool/command_line_tool.py:1434:38-47: `object` is not assignable to variable `result` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` [bad-assignment]
+ ERROR cwltool/main.py:196:59-69: Argument `object` is not assignable to parameter `inptype` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `generate_example_input` [bad-argument-type]
+ ERROR cwltool/main.py:203:59-69: Argument `object` is not assignable to parameter `inptype` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `generate_example_input` [bad-argument-type]
+ ERROR cwltool/main.py:206:63-68: Argument `object` is not assignable to parameter `inptype` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `generate_example_input` [bad-argument-type]
+ ERROR cwltool/main.py:374:27-58: Argument `bytes | str | Unknown` is not assignable to parameter `path` with type `str` in function `schema_salad.ref_resolver.file_uri` [bad-argument-type]
+ ERROR cwltool/main.py:391:12-53: Returned type `tuple[MutableMapping[Unknown, Unknown] | None, bytes | str | Any, Loader]` is not assignable to declared return type `tuple[MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | None, str, Loader]` [bad-return]
+ ERROR cwltool/main.py:902:17-73: `+` is not supported between `bytes` and `Literal['']` [unsupported-operation]
+ ERROR cwltool/main.py:902:17-73: `+` is not supported between `bytes` and `Literal['/']` [unsupported-operation]
+ ERROR cwltool/main.py:1240:48-87: `+` is not supported between `bytes` and `Literal['_tmp']` [unsupported-operation]
+ ERROR cwltool/main.py:1240:48-87: `bytes | str` is not assignable to attribute `tmp_outdir_prefix` with type `str` [bad-assignment]
+ ERROR cwltool/main.py:1331:50-55: Argument `MutableMapping[str, object]` is not assignable to parameter `doc` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None]` in function `remove_at_id` [bad-argument-type]
+ ERROR cwltool/process.py:437:46-51: Argument `object` is not assignable to parameter `field_type` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | MutableMapping[str, Unknown] | MutableSequence[Any] | MutableSequence[Unknown] | bool | float | int | str | None` in function `avroize_type` [bad-argument-type]
+ ERROR cwltool/process.py:496:40-46: Argument `object` is not assignable to parameter `obj` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `var_spool_cwl_detector` [bad-argument-type]
+ ERROR cwltool/process.py:499:40-46: Argument `object` is not assignable to parameter `obj` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `var_spool_cwl_detector` [bad-argument-type]
+ ERROR cwltool/secrets.py:46:40-50: Argument `object` is not assignable to parameter `value` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `SecretStore.has_secret` [bad-argument-type]
+ ERROR cwltool/secrets.py:50:40-50: Argument `object` is not assignable to parameter `value` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `SecretStore.has_secret` [bad-argument-type]
+ ERROR cwltool/secrets.py:62:42-43: Argument `object` is not assignable to parameter `value` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `SecretStore.retrieve` [bad-argument-type]
+ ERROR cwltool/secrets.py:64:39-40: Argument `object` is not assignable to parameter `value` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `SecretStore.retrieve` [bad-argument-type]
+ ERROR cwltool/software_requirements.py:60:40-59: `bytes | str | Any` is not assignable to attribute `tool_dependency_dir` with type `str | None` [bad-assignment]
+ ERROR cwltool/software_requirements.py:61:53-79: `bytes | str` is not assignable to attribute `dependency_resolvers_config_file` with type `str | None` [bad-assignment]
+ ERROR cwltool/update.py:135:56-57: Argument `object` is not assignable to parameter `t` with type `MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `update_secondaryFiles` [bad-argument-type]
+ ERROR cwltool/update.py:306:9-20: Object of class `object` has no attribute `lc` [missing-attribute]
+ ERROR cwltool/update.py:307:9-20: Object of class `object` has no attribute `lc` [missing-attribute]
+ ERROR cwltool/update.py:308:9-27: Cannot set item in `object` [unsupported-operation]
+ ERROR cwltool/update.py:315:15-37: Cannot index into `object` [bad-index]
+ ERROR cwltool/update.py:316:5-23: Cannot set item in `object` [unsupported-operation]
+ ERROR cwltool/update.py:318:20-32: Object of class `object` has no attribute `get` [missing-attribute]
+ ERROR cwltool/update.py:318:57-65: Object of class `object` has no attribute `get` [missing-attribute]
+ ERROR cwltool/workflow_job.py:337:28-30: Argument `object` is not assignable to parameter `sinktype` with type `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None] | MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None` in function `match_types` [bad-argument-type]
+ ERROR cwltool/workflow_job.py:344:37-48: Cannot set item in `MutableMapping[str, MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None]` [unsupported-operation]
+ ERROR cwltool/workflow_job.py:359:36-45: Argument `MutableSequence[object]` is not assignable to parameter `iterable` with type `Iterable[MutableMapping[str, Unknown] | MutableSequence[Unknown] | bool | float | int | str | None]` in function `list.extend` [bad-argument-type]

kornia (https://github.com/kornia/kornia)
+ ERROR kornia/augmentation/container/augment.py:405:35-41: Object of class `object` has no attribute `type` [missing-attribute]
+ ERROR kornia/augmentation/container/augment.py:414:35-41: Object of class `object` has no attribute `type` [missing-attribute]
+ ERROR kornia/augmentation/container/augment.py:590:25-29: Object of class `object` has no attribute `to` [missing-attribute]
+ ERROR kornia/augmentation/container/augment.py:590:73-77: Object of class `object` has no attribute `to` [missing-attribute]
+ ERROR kornia/augmentation/container/augment.py:602:25-29: Object of class `object` has no attribute `to` [missing-attribute]
+ ERROR kornia/augmentation/container/augment.py:602:71-75: Object of class `object` has no attribute `to` [missing-attribute]
+ ERROR kornia/augmentation/container/augment.py:655:29-41: Object of class `object` has no attribute `dtype` [missing-attribute]
+ ERROR kornia/augmentation/container/augment.py:656:28-35: Object of class `object` has no attribute `float` [missing-attribute]
+ ERROR kornia/augmentation/presets/ada.py:209:26-42: Object of class `object` has no attribute `size` [missing-attribute]
+ ERROR kornia/augmentation/presets/ada.py:210:22-40: Object of class `object` has no attribute `device` [missing-attribute]
+ ERROR kornia/augmentation/presets/ada.py:219:26-47: Cannot index into `object` [bad-index]
+ ERROR kornia/augmentation/presets/ada.py:233:33-52: Object of class `object` has no attribute `clone` [missing-attribute]
+ ERROR kornia/feature/dedode/transformer/dinov2.py:232:22-31: Expected a callable, got `object` [not-callable]
+ ERROR kornia/feature/dedode/transformer/dinov2.py:252:18-27: Expected a callable, got `object` [not-callable]
+ ERROR kornia/feature/dedode/transformer/dinov2.py:299:24-33: Expected a callable, got `object` [not-callable]
+ ERROR kornia/models/base.py:81:29-32: Argument `object` is not assignable to parameter `path_file` with type `Path | str` in function `kornia.io.io.write_image` [bad-argument-type]
+ ERROR kornia/models/base.py:105:29-32: Argument `object` is not assignable to parameter `path_file` with type `Path | str` in function `kornia.io.io.write_image` [bad-argument-type]
+ ERROR kornia/models/depth_estimation/base.py:53:62-73: Cannot index into `object` [bad-index]
+ ERROR kornia/models/depth_estimation/base.py:55:62-74: Object of class `object` has no attribute `device` [missing-attribute]
+ ERROR kornia/models/depth_estimation/base.py:55:82-93: Object of class `object` has no attribute `dtype` [missing-attribute]
+ ERROR kornia/models/efficient_vit/nn/ops.py:163:26-38: Argument `object | Unknown` is not assignable to parameter `out_channels` with type `int` in function `ConvLayer.__init__` [bad-argument-type]
+ ERROR kornia/models/efficient_vit/nn/ops.py:166:13-25: Argument `object | Unknown` is not assignable to parameter `in_channels` with type `int` in function `ConvLayer.__init__` [bad-argument-type]
+ ERROR kornia/models/efficient_vit/nn/ops.py:167:13-25: Argument `object | Unknown` is not assignable to parameter `out_channels` with type `int` in function `ConvLayer.__init__` [bad-argument-type]
+ ERROR kornia/models/efficient_vit/nn/ops.py:176:13-25: Argument `object | Unknown` is not assignable to parameter `in_channels` with type `int` in function `ConvLayer.__init__` [bad-argument-type]
+ ERROR kornia/models/efficient_vit/nn/ops.py:209:13-25: Argument `object | Unknown` is not assignable to parameter `out_channels` with type `int` in function `ConvLayer.__init__` [bad-argument-type]
+ ERROR kornia/models/efficient_vit/nn/ops.py:218:13-25: Argument `object | Unknown` is not assignable to parameter `in_channels` with type `int` in function `ConvLayer.__init__` [bad-argument-type]
+ ERROR kornia/models/efficient_vit/nn/ops.py:248:26-38: Argument `object | Unknown` is not assignable to parameter `out_channels` with type `int` in function `ConvLayer.__init__` [bad-argument-type]
+ ERROR kornia/models/efficient_vit/nn/ops.py:251:13-25: Argument `object | Unknown` is not assignable to parameter `in_channels` with type `int` in function `ConvLayer.__init__` [bad-argument-type]
+ ERROR kornia/models/segmentation/base.py:63:44-55: Cannot index into `object` [bad-index]
+ ERROR kornia/models/segmentation/base.py:175:20-38: Object of class `object` has no attribute `ndim` [missing-attribute]
+ ERROR kornia/models/segmentation/base.py:176:87-106: Object of class `object` has no attribute `shape` [missing-attribute]
+ ERROR kornia/models/segmentation/base.py:178:44-62: Object of class `object` has no attribute `size` [missing-attribute]
+ ERROR kornia/models/segmentation/base.py:229:61-76: Cannot index into `object` [bad-index]
+ ERROR kornia/models/segmentation/base.py:229:83-105: Cannot index into `object` [bad-index]
+ ERROR kornia/utils/helpers.py:382:55-60: Argument `object` is not assignable to parameter `dict_obj` with type `dict[str, Any]` in function `dict_to_dataclass` [bad-argument-type]

cki-lib (https://gitlab.com/cki-project/cki-lib)
+ ERROR cki_lib/config_tree.py:31:46-52: Argument `object` is not assignable to parameter `key` with type `str` in function `_merged` [bad-argument-type]
+ ERROR cki_lib/logger.py:87:60-65: Argument `object` is not assignable to parameter `obj` with type `dict[str, Any]` in function `PackFormatter.flatten` [bad-argument-type]
+ ERROR cki_lib/misc.py:85:20-81: `object | Any` is not assignable to variable `data` with type `dict[str, Any] | list[Any]` [bad-assignment]
+ ERROR cki_lib/misc.py:119:20-37: `object` is not assignable to variable `data` with type `dict[str, Any] | list[Any]` [bad-assignment]
+ ERROR cki_lib/yaml.py:264:5-31: Cannot set item in `object` [unsupported-operation]
+ ERROR cki_lib/yaml.py:272:9-35: Cannot delete item in `object` [unsupported-operation]

dulwich (https://github.com/dulwich/dulwich)
+ ERROR dulwich/cli.py:1613:18-26: Argument `bytes | str` is not assignable to parameter `basename` with type `str` in function `dulwich.pack.Pack.__init__` [bad-argument-type]
+ ERROR dulwich/graph.py:212:21-28: Type `SupportsDunderGT[Any]` is not iterable [not-iterable]
+ ERROR dulwich/graph.py:212:21-28: Type `SupportsDunderLT[Any]` is not iterable [not-iterable]
+ ERROR dulwich/porcelain/__init__.py:1792:44-60: No matching overload found for function `posixpath.join` called with arguments: (str, bytes | str) [no-matching-overload]
+ ERROR dulwich/porcelain/__init__.py:1798:49-70: No matching overload found for function `posixpath.join` called with arguments: (str, bytes | str) [no-matching-overload]
+ ERROR dulwich/porcelain/__init__.py:1804:49-82: No matching overload found for function `posixpath.join` called with arguments: (bytes | str | Unknown, bytes | str | Unknown) [no-matching-overload]
+ ERROR dulwich/reftable.py:985:13-47: Type `SupportsDunderGT[Any]` is not iterable [not-iterable]
+ ERROR dulwich/reftable.py:985:13-47: Type `SupportsDunderLT[Any]` is not iterable [not-iterable]

alerta (https://github.com/alerta/alerta)
+ ERROR alerta/models/alert.py:238:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `Alert.from_document` [bad-argument-type]
+ ERROR alerta/models/blackout.py:215:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `Blackout.from_document` [bad-argument-type]
+ ERROR alerta/models/customer.py:59:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `Customer.from_document` [bad-argument-type]
+ ERROR alerta/models/group.py:123:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `Group.from_document` [bad-argument-type]
+ ERROR alerta/models/heartbeat.py:151:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `Heartbeat.from_document` [bad-argument-type]
+ ERROR alerta/models/key.py:116:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `ApiKey.from_document` [bad-argument-type]
+ ERROR alerta/models/note.py:103:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `Note.from_document` [bad-argument-type]
+ ERROR alerta/models/permission.py:64:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `Permission.from_document` [bad-argument-type]
+ ERROR alerta/models/user.py:142:38-39: Argument `dict[object, object]` is not assignable to parameter `doc` with type `dict[str, Any]` in function `User.from_document` [bad-argument-type]

hydpy (https://github.com/hydpy-dev/hydpy)
+ ERROR hydpy/auxs/armatools.py:802:54-804:10: No matching overload found for function `numpy.linalg._linalg.lstsq` called with arguments: (ndarray[tuple[Any, ...], dtype[float64]], ndarray[tuple[Any, ...], dtype[generic[Any]]], rcond=Literal[-1]) [no-matching-overload]
+ ERROR hydpy/auxs/calibtools.py:286:35-60: `*` is not supported between `float` and `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
+ ERROR hydpy/auxs/calibtools.py:288:28-56: `*` is not supported between `float` and `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
+ ERROR hydpy/auxs/calibtools.py:719:51-62: `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to upper bound `float | ndarray[tuple[Any, ...], dtype[float64]]` of type variable `ArrayFloat` [bad-specialization]
+ ERROR hydpy/auxs/validtools.py:74:13-38: `<` is not supported between `generic[Any]` and `float` [unsupported-operation]
+ ERROR hydpy/core/importtools.py:1352:27-67: `bytes | str` is not assignable to variable `controlfile` with type `str | None` [bad-assignment]
+ ERROR hydpy/core/itemtools.py:1564:22-40: `+` is not supported between `ndarray[tuple[Any, ...], dtype[generic[Any]]]` and `ndarray[tuple[Any, ...], dtype[float64]]` [unsupported-operation]
+ ERROR hydpy/core/itemtools.py:1636:22-40: `*` is not supported between `ndarray[tuple[Any, ...], dtype[generic[Any]]]` and `ndarray[tuple[Any, ...], dtype[float64]]` [unsupported-operation]
+ ERROR hydpy/core/masktools.py:229:56-77: `<` is not supported between `generic[Any]` and `Literal[1]` [unsupported-operation]
+ ERROR hydpy/core/masktools.py:243:18-36: Unary `~` is not supported on `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
- ERROR hydpy/core/masktools.py:299:22-47: Cannot index into `ndarray[tuple[Any, ...], dtype[Any]]` [bad-index]
+ ERROR hydpy/core/masktools.py:299:22-47: Cannot index into `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [bad-index]
- ERROR hydpy/core/masktools.py:300:19-27: No matching overload found for function `set.__init__` called with arguments: (bool | float | int | ndarray[tuple[Any, ...], dtype[Any]] | Unknown) [no-matching-overload]
+ ERROR hydpy/core/masktools.py:300:19-27: No matching overload found for function `set.__init__` called with arguments: (bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]] | Unknown) [no-matching-overload]
- ERROR hydpy/core/modeltools.py:3456:33-76: No matching overload found for function `range.__new__` called with arguments: (type[range], bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]) [no-matching-overload]
+ ERROR hydpy/core/modeltools.py:3456:33-76: No matching overload found for function `range.__new__` called with arguments: (type[range], bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]) [no-matching-overload]
- ERROR hydpy/core/modeltools.py:3458:33-71: No matching overload found for function `range.__new__` called with arguments: (type[range], bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]) [no-matching-overload]
+ ERROR hydpy/core/modeltools.py:3458:33-71: No matching overload found for function `range.__new__` called with arguments: (type[range], bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]) [no-matching-overload]
- ERROR hydpy/core/modeltools.py:3514:25-62: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `value` with type `float` in function `SubstepModel.timeleft` [bad-argument-type]
+ ERROR hydpy/core/modeltools.py:3514:25-62: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `value` with type `float` in function `SubstepModel.timeleft` [bad-argument-type]
- ERROR hydpy/core/modeltools.py:4050:13-53: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `double` with type `float` in function `hydpy.cythons.modelutils.isnan` [bad-argument-type]
+ ERROR hydpy/core/modeltools.py:4050:13-53: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `double` with type `float` in function `hydpy.cythons.modelutils.isnan` [bad-argument-type]
+ ERROR hydpy/core/modeltools.py:4061:17-60: `*` is not supported between `float` and `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
+ ERROR hydpy/core/modeltools.py:4578:40-72: No matching overload found for function `max` called with arguments: (float, generic[Any]) [no-matching-overload]
- ERROR hydpy/core/modeltools.py:4059:34-4063:14: No matching overload found for function `min` called with arguments: (float, float | ndarray[tuple[Any, ...], dtype[float64]], Unknown) [no-matching-overload]
+ ERROR hydpy/core/modeltools.py:4585:44-4587:18: No matching overload found for function `max` called with arguments: (float, generic[Any]) [no-matching-overload]
+ ERROR hydpy/core/objecttools.py:2022:28-29: Argument `object` is not assignable to parameter `ys` with type `Mapping[str, Unknown] | Sequence[Unknown] | float | ndarray[tuple[Any, ...], dtype[float64]]` in function `is_equal` [bad-argument-type]
+ ERROR hydpy/core/parametertools.py:1788:48-61: `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to upper bound `float | ndarray[tuple[Any, ...], dtype[float64]]` of type variable `ArrayFloat` [bad-specialization]
+ ERROR hydpy/core/parametertools.py:1794:43-55: `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to upper bound `float | ndarray[tuple[Any, ...], dtype[float64]]` of type variable `ArrayFloat` [bad-specialization]
+ ERROR hydpy/core/parametertools.py:2374:42-50: `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to upper bound `float | ndarray[tuple[Any, ...], dtype[float64]]` of type variable `ArrayFloat` [bad-specialization]
+ ERROR hydpy/core/parametertools.py:2435:24-42: Unary `~` is not supported on `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
+ ERROR hydpy/core/parametertools.py:2442:48-56: `ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to upper bound `float | ndarray[tuple[Any, ...], dtype[float64]]` of type variable `ArrayFloat` [bad-specialization]
+ ERROR hydpy/core/parametertools.py:2842:43-51: `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to upper bound `float | ndarray[tuple[Any, ...], dtype[float64]]` of type variable `ArrayFloat` [bad-specialization]
+ ERROR hydpy/core/parametertools.py:3414:40-53: `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to upper bound `float | ndarray[tuple[Any, ...], dtype[float64]]` of type variable `ArrayFloat` [bad-specialization]
- ERROR hydpy/core/parametertools.py:3423:38-63: No matching overload found for function `zip.__new__` called with arguments: (type[zip[_T_co]], tuple[str, ...], bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]) [no-matching-overload]
+ ERROR hydpy/core/parametertools.py:3423:38-63: No matching overload found for function `zip.__new__` called with arguments: (type[zip[_T_co]], tuple[str, ...], bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]) [no-matching-overload]
+ ERROR hydpy/core/parametertools.py:3894:40-53: `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to upper bound `float | ndarray[tuple[Any, ...], dtype[float64]]` of type variable `ArrayFloat` [bad-specialization]
+ ERROR hydpy/core/parametertools.py:4077:22-46: `<` is not supported between `ndarray[tuple[Any, ...], dtype[generic[Any]]]` and `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
+ ERROR hydpy/core/sequencetools.py:818:53-63: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `x` with type `float | ndarray[tuple[Any, ...], dtype[float64]]` in function `copy.deepcopy` [bad-argument-type]
+ ERROR hydpy/core/sequencetools.py:2095:30-35: Argument `ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `array` with type `ndarray[tuple[Any, ...], dtype[float64]]` in function `InfoArray.__new__` [bad-argument-type]
- ERROR hydpy/core/variabletools.py:1680:20-30: Returned type `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to declared return type `ndarray[tuple[Any, ...], dtype[Unknown]]` [bad-return]
+ ERROR hydpy/core/variabletools.py:1680:20-30: Returned type `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to declared return type `ndarray[tuple[Any, ...], dtype[Unknown]]` [bad-return]
- ERROR hydpy/core/variabletools.py:1855:24-34: Returned type `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to declared return type `float` [bad-return]
+ ERROR hydpy/core/variabletools.py:1855:24-34: Returned type `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to declared return type `float` [bad-return]
+ ERROR hydpy/core/variabletools.py:2070:16-27: Unary `+` is not supported on `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
+ ERROR hydpy/core/variabletools.py:2073:16-27: Unary `-` is not supported on `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
- ERROR hydpy/core/variabletools.py:2076:20-30: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `x` with type `SupportsAbs[int]` in function `abs` [bad-argument-type]
+ ERROR hydpy/core/variabletools.py:2076:20-30: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `x` with type `SupportsAbs[int]` in function `abs` [bad-argument-type]
+ ERROR hydpy/core/variabletools.py:2079:16-32: `/` is not supported between `float` and `ndarray[tuple[Any, ...], dtype[generic[Any]]]` [unsupported-operation]
+ ERROR hydpy/core/variabletools.py:2082:18-35: `//` is not supported between `ndarray[tuple[Any, ...], dtype[generic[Any]]]` and `float` [unsupported-operation]
+ ERROR hydpy/core/variabletools.py:2218:27-48: No matching overload found for function `numpy._core.fromnumeric.around` called with arguments: (bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]], int) [no-matching-overload]
- ERROR hydpy/exe/xmltools.py:2340:53-61: Argument `type[AddItem] | type[GetItem] | type[MultiplyItem] | type[SetItem]` is not assignable to parameter `itemtype` with type `type[AddItem]` in function `XMLVar._get_changeitem` [bad-argument-type]
+ ERROR hydpy/exe/xmltools.py:2340:53-61: Argument `type[AddItem] | type[GetItem] | type[MultiplyItem] | type[SetItem]` is not assignable to parameter `itemtype` with type `type[AddItem | MultiplyItem | SetItem]` in function `XMLVar._get_changeitem` [bad-argument-type]
- ERROR hydpy/models/arma/arma_derived.py:45:29-39: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
+ ERROR hydpy/models/arma/arma_derived.py:45:29-39: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
- ERROR hydpy/models/arma/arma_derived.py:46:30-40: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
+ ERROR hydpy/models/arma/arma_derived.py:46:30-40: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
- ERROR hydpy/models/arma/arma_derived.py:47:28-38: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
+ ERROR hydpy/models/arma/arma_derived.py:47:28-38: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
- ERROR hydpy/models/arma/arma_derived.py:48:28-38: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
+ ERROR hydpy/models/arma/arma_derived.py:48:28-38: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
- ERROR hydpy/models/conv/conv_derived.py:32:34-44: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
+ ERROR hydpy/models/conv/conv_derived.py:32:34-44: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
- ERROR hydpy/models/conv/conv_derived.py:78:34-44: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
+ ERROR hydpy/models/conv/conv_derived.py:78:34-44: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `value` with type `int | tuple[int, ...]` in function `hydpy.core.propertytools.BaseProperty.__set__` [bad-argument-type]
- ERROR hydpy/models/conv/conv_derived.py:138:38-47: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `obj` with type `Sized` in function `len` [bad-argument-type]
+ ERROR hydpy/models/conv/conv_derived.py:138:38-47: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `obj` with type `Sized` in function `len` [bad-argument-type]
- ERROR hydpy/models/conv/conv_derived.py:138:54-62: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `obj` with type `Sized` in function `len` [bad-argument-type]
+ ERROR hydpy/models/conv/conv_derived.py:138:54-62: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `obj` with type `Sized` in function `len` [bad-argument-type]
- ERROR hydpy/models/conv/conv_derived.py:139:40-49: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `iterable` with type `Iterable[@_]` in function `enumerate.__new__` [bad-argument-type]
+ ERROR hydpy/models/conv/conv_derived.py:139:40-49: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]` is not assignable to parameter `iterable` with type `Iterable[@_]` in function `enumerate.__new__` [bad-argument-type]
- ERROR hydpy/models/conv/conv_derived.py:196:27-77: No matching overload found for function `numpy._core.multiarray._ConstructorEmpty.__call__` called with arguments: (tuple[int, bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]], dtype=type[signedinteger[_64Bit]]) [no-matching-overload]
+ ERROR hydpy/models/conv/conv_derived.py:196:27-77: No matching overload found for function `numpy._core.multiarray._ConstructorEmpty.__call__` called with arguments: (tuple[int, bool | float | int | ndarray[tuple[Any, ...], dtype[generic[Any]]]], dtype=type[signedinteger[_64Bit]]) [no-matching-overload]
- ERROR hydpy/models/conv/conv_derived.py:196:33-42: Argument `bool | float | int | ndarray[tuple[Any, ...], dtype[Any]]` is not assignable to parameter `obj` with type `Sized` in function `len` [bad-argument-type]

... (truncated 456 lines) ...

django-stubs (https://github.com/typeddjango/django-stubs)
+ ERROR ext/django_stubs_ext/patch.py:114:9-15: Object of class `object` has no attribute `cls` [missing-attribute]

dd-trace-py (https://github.com/DataDog/dd-trace-py)
+ ERROR ddtrace/_trace/utils_botocore/span_pointers/dynamodb.py:663:16-26: Returned type `dict[str, object]` is not assignable to declared return type `dict[str, str] | None` [bad-return]
+ ERROR ddtrace/appsec/_trace_utils.py:54:34-65: Argument `tuple[str, object, int]` is not assignable to parameter `object` with type `tuple[str, dict[Unknown, Unknown], int]` in function `list.append` [bad-argument-type]
- ERROR ddtrace/commands/ddtrace_run.py:98:33-56: No matching overload found for function `posixpath.join` called with arguments: (object, Literal['bootstrap']) [no-matching-overload]
+ ERROR ddtrace/commands/ddtrace_run.py:98:33-56: No matching overload found for function `posixpath.join` called with arguments: (LiteralString | bytes | str, Literal['bootstrap']) [no-matching-overload]
- ERROR ddtrace/contrib/internal/botocore/services/bedrock.py:303:12-58: Returned type `dict[str, list[str | Unknown | None] | list[Any] | list[Unknown]]` is not assignable to declared return type `dict[str, list[str]]` [bad-return]
+ ERROR ddtrace/contrib/internal/botocore/services/bedrock.py:303:12-58: Returned type `dict[str, list[str | Unknown | None] | list[object]]` is not assignable to declared return type `dict[str, list[str]]` [bad-return]
+ ERROR ddtrace/contrib/internal/botocore/services/bedrock.py:358:12-58: Returned type `dict[str, list[str | Any] | list[str | Unknown] | list[object]]` is not assignable to declared return type `dict[str, list[str]]` [bad-return]
+ ERROR ddtrace/contrib/internal/flask_cache/utils.py:47:29-54: Object of class `object` has no attribute `address` [missing-attribute]
- ERROR ddtrace/contrib/internal/pylibmc/client.py:130:104-113: Cannot index into `Iterable[Unknown]` [bad-index]
+ ERROR ddtrace/contrib/internal/pylibmc/client.py:130:104-113: Cannot index into `Iterable[object]` [bad-index]
+ ERROR ddtrace/contrib/internal/ray/patch.py:539:9-29: Object of class `object` has no attribute `__signature__` [missing-attribute]
+ ERROR ddtrace/contrib/internal/ray/patch.py:543:36-42: Argument `object` is not assignable to parameter `wrapped` with type `(ParamSpec(@_)) -> @_` in function `functools.wraps` [bad-argument-type]
+ ERROR ddtrace/contrib/internal/ray/patch.py:543:72-78: Argument `object` is not assignable to parameter `method` with type `(...) -> Any` in function `_job_supervisor_run_wrapper` [bad-argument-type]
+ ERROR ddtrace/contrib/internal/ray/patch.py:545:36-42: Argument `object` is not assignable to parameter `wrapped` with type `(ParamSpec(@_)) -> @_` in function `functools.wraps` [bad-argument-type]
+ ERROR ddtrace/contrib/internal/ray/patch.py:545:69-75: Argument `object` is not assignable to parameter `method` with type `(...) -> Any` in function `_exec_entrypoint_wrapper` [bad-argument-type]
+ ERROR ddtrace/contrib/internal/ray/patch.py:550:40-46: Argument `object` is not assignable to parameter `wrapped` with type `(ParamSpec(@_)) -> @_` in function `functools.wraps` [bad-argument-type]
+ ERROR ddtrace/contrib/internal/ray/patch.py:550:77-83: Argument `object` is not assignable to parameter `method` with type `(...) -> Any` in function `_inject_tracing_actor_method` [bad-argument-type]
+ ERROR ddtrace/debugging/_probe/remoteconfig.py:312:12-48: `>` is not supported between `float` and `SupportsComplex` [unsupported-operation]
+ ERROR ddtrace/debugging/_probe/remoteconfig.py:312:12-48: `>` is not supported between `float` and `SupportsFloat` [unsupported-operation]
+ ERROR ddtrace/debugging/_probe/remoteconfig.py:312:12-48: `>` is not supported between `float` and `SupportsIndex` [unsupported-operation]
+ ERROR ddtrace/debugging/_probe/remoteconfig.py:312:12-48: `>` is not supported between `float` and `SupportsInt` [unsupported-operation]
+ ERROR ddtrace/internal/ci_visibility/git_client.py:500:85-101: Object of class `bytes` has no attribute `encode` [missing-attribute]
+ ERROR ddtrace/internal/coverage/report.py:209:51-213:10: No matching overload found for function `sorted` called with arguments: (set[object]) [no-matching-overload]
+ ERROR ddtrace/internal/coverage/report.py:214:50-217:10: No matching overload found for function `sorted` called with arguments: (set[object]) [no-matching-overload]
+ ERROR ddtrace/internal/coverage/report.py:219:51-222:10: No matching overload found for function `sorted` called with arguments: (set[object]) [no-matching-overload]
+ ERROR ddtrace/internal/coverage/report.py:223:50-226:10: No matching overload found for function `sorted` called with arguments: (set[object]) [no-matching-overload]
+ ERROR ddtrace/internal/utils/http.py:452:22-76: No matching overload found for function `dict.__init__` called with arguments: (Generator[list[str], None, None]) [no-matching-overload]
+ ERROR ddtrace/llmobs/_evaluators/ragas/faithfulness.py:170:20-30: Returned type `list[object]` is not assignable to declared return type `list[str] | None` [bad-return]
+ ERROR ddtrace/llmobs/_experiment.py:319:77-96: Cannot set item in `dict[tuple[str, str], Never]` [unsupported-operation]
+ ERROR ddtrace/llmobs/_experiment.py:328:63-75: Cannot set item in `dict[tuple[str, str], Never]` [unsupported-operation]
+ ERROR ddtrace/llmobs/_integrations/langchain.py:509:32-43: Type `object` is not iterable [not-iterable]
+ ERROR ddtrace/llmobs/_integrations/langchain.py:734:33-47: Object of class `object` has no attribute `page_content` [missing-attribute]
+ ERROR ddtrace/llmobs/_utils.py:124:20-33: Type `object` is not iterable [not-iterable]
+ ERROR ddtrace/llmobs/_utils.py:131:39-46: Cannot set item in `dict[str, dict[str, Any] | list[dict[str, str]] | list[str] | list[Unknown] | str]` [unsupported-operation]
+ ERROR ddtrace/llmobs/_utils.py:133:41-50: Cannot set item in `dict[str, dict[str, Any] | list[dict[str, str]] | list[str] | list[Unknown] | str]` [unsupported-operation]
+ ERROR ddtrace/llmobs/_utils.py:135:40-48: Cannot set item in `dict[str, dict[str, Any] | list[dict[str, str]] | list[str] | list[Unknown] | str]` [unsupported-operation]
+ ERROR ddtrace/llmobs/_utils.py:139:36-40: Cannot set item in `dict[str, dict[str, Any] | list[dict[str, str]] | list[str] | list[Unknown] | str]` [unsupported-operation]
+ ERROR ddtrace/vendor/ply/yacc.py:1339:57-68: No matching overload found for function `str.join` called with arguments: (tuple[object, ...]) [no-matching-overload]
- ERROR ddtrace/vendor/ply/yacc.py:1437:27-43: `tuple[Unknown, ...]` is not assignable to attribute `prod` with type `list[Unknown]` [bad-assignment]
+ ERROR ddtrace/vendor/ply/yacc.py:1437:27-43: `tuple[object, ...]` is not assignable to attribute `prod` with type `list[Unknown]` [bad-assignment]
+ ERROR ddtrace/vendor/ply/yacc.py:2982:20-24: Cannot index into `SupportsDunderGT[Any]` [bad-index]
+ ERROR ddtrace/vendor/ply/yacc.py:2982:20-24: Cannot index into `SupportsDunderLT[Any]` [bad-index]
+ ERROR ddtrace/vendor/ply/yacc.py:2983:34-38: Cannot index into `SupportsDunderGT[Any]` [bad-index]
+ ERROR ddtrace/vendor/ply/yacc.py:2983:34-38: Cannot index into `SupportsDunderLT[Any]` [bad-index]
+ ERROR ddtrace/vendor/ply/yacc.py:3158:13-36: Type `SupportsDunderGT[Any]` is not iterable [not-iterable]
+ ERROR ddtrace/vendor/ply/yacc.py:3158:13-36: Type `SupportsDunderLT[Any]` is not iterable [not-iterable]
+ ERROR scripts/validate_wheel.py:68:28-49: No matching overload found for function `sorted` called with arguments: (set[object]) [no-matching-overload]
- ERROR scripts/validate_wheel.py:74:28-48: No matching overload found for function `sorted` called with arguments: (set[Unknown | None]) [no-matching-overload]
+ ERROR scripts/validate_wheel.py:74:28-48: No matching overload found for function `sorted` called with arguments: (set[object]) [no-matching-overload]
- ERROR scripts/validate_wheel.py:84:36-45: Argument `Unknown | None` is not assignable to parameter `name` with type `ZipInfo | str` in function `zipfile.ZipFile.read` [bad-argument-type]
+ ERROR scripts/validate_wheel.py:84:36-45: Argument `object` is not assignable to parameter `name` with type `ZipInfo | str` in function `zipfile.ZipFile.read` [bad-argument-type]
+ ERROR tests/appsec/iast/fixtures/taint_sinks/path_traversal.py:17:32-77: No matching overload found for function `genericpath.commonprefix` called with arguments: (tuple[bytes | str, str]) [no-matching-overload]
+ ERROR tests/commands/test_runner.py:35:40-53: No matching overload found for function `str.join` called with arguments: (list[bytes | str]) [no-matching-overload]
+ ERROR tests/conftest.py:684:54-57: Argument `object` is not assignable to parameter `req` with type `dict[str, Any]` in function `TelemetryTestSession._get_request_bodies` [bad-argument-type]
+ ERROR tests/conftest.py:737:28-37: Cannot index into `SupportsDunderGT[Any]` [bad-index]
+ ERROR tests/conftest.py:737:28-37: Cannot index into `SupportsDunderLT[Any]` [bad-index]
+ ERROR tests/conftest.py:742:17-22: Object of class `SupportsDunderGT` has no attribute `pop`
+ Object of class `SupportsDunderLT` has no attribute `pop` [missing-attribute]
+ ERROR tests/llmobs/test_experiments.py:500:16-31: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:501:16-36: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:691:12-32: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:692:12-37: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:693:12-30: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:695:12-32: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:696:12-37: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:697:12-30: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:1198:12-32: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:1199:12-37: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:1200:12-32: Cannot index into `object` [bad-index]
+ ERROR tests/llmobs/test_experiments.py:1201:12-37: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_telemetry.py:373:12-38: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_telemetry.py:374:12-39: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_telemetry.py:376:12-38: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_telemetry.py:377:12-39: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_telemetry.py:379:12-38: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_telemetry.py:380:12-39: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_telemetry.py:382:12-38: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_telemetry.py:383:12-39: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_writer.py:1170:12-38: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_writer.py:1171:12-39: Cannot index into `object` [bad-index]
+ ERROR tests/telemetry/test_writer.py:1172:12-39: Cannot index into `object` [bad-index]

... (truncated 1940 lines) ...```

samwgoldman · 2026-01-05T22:03:29Z

Thanks for investigating! This is a clever idea, but I think solving the variable to its bound is a bit problematic. It looks like the new errors in mypy primer arise from this as well.

I know our current behavior of solving a type variable to the "first" concrete type it sees in constraints leads to issues like this. I took a moment to analyze this example against our currently planned design for improving type variable solving. First, let's simplify the example a little bit:

from collections.abc import Callable

def f[T: int](g: Callable[[T], T]):
    pass

def g(x: int|str) -> int:
    return 0

f(g)

Here, we are passing a callable type int|str -> int into a position expecting T -> T, and we want to solve for T.

* create fresh X <: int, substitute to get `f' : X -> None`
* int|str -> None <: X -> None  [call f'(g)]
   * X <: int | str             [func arg contravariant]
      * X = int | str           [eager variable solution *]
   * int <: X                   [func return covariant]
      * int <: int|str          [X=int|str]
* int|str <: int                [check solution against bound **]

Things go "wrong" when we eagerly solve for X (*) and we realize later when we go check against the bound (**).

Notice that we see both X <: int|str and int <: X when checking the call. If we considered both of these constraints together, we would see that the better, more precise solution for T is int. In general, solving a type variable to an upper bound when a lower bound exists will be imprecise -- this is also why solving to the typevar bound, an upper bound, leads to errors.

Delaying the solution, solving #105, seems like the best solution to this problem as well.

rchen152 · 2026-01-08T23:38:04Z

I'm going to close this PR, since it sounds like we should work on a more general solution for #105 instead.

Fix bad-specialization false positive for bounded TypeVar in callable (…

e3d6662

…facebook#1960)

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Fix bounded TypeVar resolution in early return path

70b8168

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yangdanny97 mentioned this pull request Jan 5, 2026

False positive bad-specialization #1960

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Fix bad-specialization false positive for bounded TypeVar in callable (#1960) #1974

Fix bad-specialization false positive for bounded TypeVar in callable (#1960) #1974

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Fix bad-specialization false positive for bounded TypeVar in callable (#1960) #1974

Fix bad-specialization false positive for bounded TypeVar in callable (#1960) #1974

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jackulau commented Dec 31, 2025

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