Typecheck unreachable code #18707

A5rocks · 2025-02-19T09:43:22Z

Mypy doesn't typecheck unreachable code and this is surprising to many. This is an attempt at fixing that. It's a draft until:

I list out the issues fixed (done)
I fix the bugs raised by the test cases (done)
I fix the bugs raised by mypy primer (done)
I get feedback that this is fine (skipped for now)
I put this behind a flag (we can bundle this in --strict maybe and hopefully enable it by default in 2.0) (skipped for now, I will add after reviews)

Problem areas based on test cases:

currently we use None for unreachable type maps but we want to know what is unreachable to mark it as Never (fixed what was relevant in tests. narrowing is not guaranteed by mypy and we can fix things in the future -- I'd rather have context for any fixes)
- it doesn't seem too bad to mark unreachability based on if a variable has a Never type
analyzing a function multiple times for type var values (fixed)
- I think I can disable this new behavior based on if we're in a function like that?
reporting unreachability multiple times (block in a block) (fixed)
- blocks could store unreachability report status
exports could change (see check-incremental.test's changes)
- I think this is fine?
Never doesn't support operations (e.g. <Never>.f(), <Never> > 5) (fixed)
- it should return Never for these, I think?

Also maybe reveal_type(<Never>) should be non-trivial. (fixed)

Generally I tried enabling --warn-unreachable in a test case if it looked like people were relying on un-checked unreachable code as a test. Also obviously many of the test case changes are wrong I just did not have the energy to fix all the bugs (and honestly maybe should think through the two things above -- the first especially was a source of issues).

I also have no clue what mypyc does so the test change there could be awful.

Except things important enough we marked them before, which include: - `if not typing.TYPE_CHECKING` - platform checks that do not match

…bility

This is an awful hack but the documentation says: > Ask a static type checker to confirm that a line of code is > unreachable. as well as something specifically about `Never` (it's confusing)

A5rocks · 2025-03-06T09:43:46Z

I am happy with how the test changes are now. I'll update code a bit based on mypy primer results but I think this is mostly final.

I don't know how to test this.

A5rocks · 2025-03-13T10:09:21Z

Alright, I went through mypy-primer. ... well, skimmed over at the end, but whatever. The biggest thing that feels wrong but actually isn't is something like this:

x: int
if isinstance(x, int):
    raise ValueError()

reveal_type(x)  # <- this is not Never

This is because the end of both branches are unreachable. It's impossible to get to that reveal_type through the if branch (an error is unconditionally raised) and the same for the else branch (an int is always a subclass of an int). Therefore something must be lying to mypy and importantly mypy does not know what. So it can't narrow. (this is a justification -- I'm not sure if the reason this actually happens is a is None check or something. But it works just fine and probably should remain. In fact, I'll add a test for this)

github-actions · 2025-03-13T10:41:02Z

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

beartype (https://github.com/beartype/beartype)
+ beartype/_util/cache/utilcachecall.py:575: error: Incompatible return value type (got "Callable[..., Any]", expected "CallableT")  [return-value]
- beartype/_util/func/utilfuncmake.py:310: error: Unused "type: ignore" comment  [unused-ignore]

vision (https://github.com/pytorch/vision)
+ torchvision/transforms/v2/_augment.py:82: error: Incompatible types in assignment (expression has type "None", variable has type "list[float]")  [assignment]

speedrun.com_global_scoreboard_webapp (https://github.com/Avasam/speedrun.com_global_scoreboard_webapp)
+ backend/services/utils.py:71: error: Incompatible return value type (got "SrcErrorResultDto", expected "dict[Literal['data'], Any] | None")  [return-value]

dragonchain (https://github.com/dragonchain/dragonchain)
+ dragonchain/lib/keys.py:60:49: error: "None" has no attribute "pubkey"  [attr-defined]
+ dragonchain/lib/keys.py:277:80: error: Argument 4 to "sign_l1_block" has incompatible type "BlockModel"; expected "L1BlockModel"  [arg-type]
+ dragonchain/lib/keys.py:279:80: error: Argument 4 to "sign_l2_block" has incompatible type "BlockModel"; expected "L2BlockModel"  [arg-type]
+ dragonchain/lib/keys.py:281:80: error: Argument 4 to "sign_l3_block" has incompatible type "BlockModel"; expected "L3BlockModel"  [arg-type]
+ dragonchain/lib/keys.py:283:80: error: Argument 4 to "sign_l4_block" has incompatible type "BlockModel"; expected "L4BlockModel"  [arg-type]
+ dragonchain/lib/keys.py:285:80: error: Argument 4 to "sign_l5_block" has incompatible type "BlockModel"; expected "L5BlockModel"  [arg-type]

schema_salad (https://github.com/common-workflow-language/schema_salad)
+ schema_salad/ref_resolver.py: note: In member "validate_link" of class "Loader":
+ schema_salad/ref_resolver.py:1093:20: error: Incompatible return value type (got "None", expected "str | CommentedSeq | CommentedMap")  [return-value]

prefect (https://github.com/PrefectHQ/prefect)
+ src/prefect/settings/sources.py:118: error: Unsupported right operand type for in ("Optional[list[str]]")  [operator]
+ src/prefect/_internal/concurrency/cancellation.py:181: error: Unsupported left operand type for > ("None")  [operator]
+ src/prefect/server/database/dependencies.py:304: error: "Self" has no attribute "_func"  [attr-defined]
+ src/prefect/client/orchestration/__init__.py:319: error: Setting? has no attribute "value"  [attr-defined]
+ src/prefect/client/orchestration/__init__.py:809: error: Incompatible types in assignment (expression has type "int", variable has type "list[float]")  [assignment]
+ src/prefect/client/orchestration/__init__.py:1327: error: Setting? has no attribute "value"  [attr-defined]
+ src/prefect/client/orchestration/__init__.py:1605: error: Incompatible types in assignment (expression has type "int", variable has type "list[float]")  [assignment]
+ src/prefect/concurrency/v1/sync.py:69: error: Value of type "Coroutine[Any, Any, R?]" must be used  [unused-coroutine]
+ src/prefect/concurrency/v1/sync.py:69: note: Are you missing an await?
- src/prefect/server/models/deployments.py:744: error: "Never" has no attribute "model_dump"  [attr-defined]
+ src/prefect/workers/base.py:699: error: Setting? has no attribute "value"  [attr-defined]
+ src/prefect/input/run_input.py:553: error: Incompatible return value type (got "Coroutine[Any, Any, R?]", expected "Union[T, AutomaticRunInput[T]]")  [return-value]
+ src/prefect/flow_runs.py:322: error: Item "None" of "Optional[State[Any]]" has no attribute "is_running"  [union-attr]
+ src/prefect/flow_runs.py:325: error: Item "type" of "Union[type[AutomaticRunInput[Never]], type[T]]" has no attribute "load"  [union-attr]
+ src/prefect/flow_runs.py:326: error: Return value expected  [return-value]
- src/prefect/cli/deploy.py:872: error: Need type annotation for "active_workers" (hint: "active_workers: list[<type>] = ...")  [var-annotated]

static-frame (https://github.com/static-frame/static-frame)
+ static_frame/core/frame.py:5721: error: Unused "type: ignore" comment  [unused-ignore]

altair (https://github.com/vega/altair)
+ tools/schemapi/codegen.py:153: error: Set comprehension has incompatible type Set[set[str]]; expected Set[str]  [misc]
+ tools/schemapi/codegen.py:154: error: Set comprehension has incompatible type Set[set[str]]; expected Set[str]  [misc]
+ tools/schemapi/codegen.py:156: error: Set comprehension has incompatible type Set[set[str]]; expected Set[str]  [misc]

trio (https://github.com/python-trio/trio)
+ src/trio/testing/_raises_group.py:720: error: Unsupported left operand type for + ("None")  [operator]
+ src/trio/_core/_tests/test_io.py:348: error: "_EpollStatistics" has no attribute "monitors"  [attr-defined]
+ src/trio/_core/_tests/test_io.py:349: error: "_EpollStatistics" has no attribute "tasks_waiting"; maybe "tasks_waiting_read" or "tasks_waiting_write"?  [attr-defined]
+ src/trio/_core/_tests/test_io.py:399: error: "_EpollStatistics" has no attribute "monitors"  [attr-defined]
+ src/trio/_core/_tests/test_io.py:400: error: "_EpollStatistics" has no attribute "tasks_waiting"; maybe "tasks_waiting_read" or "tasks_waiting_write"?  [attr-defined]
+ src/trio/_tests/test_subprocess.py:370: error: No overload variant of "run_process" matches argument types "list[str]", "str"  [call-overload]
+ src/trio/_tests/test_subprocess.py:370: note: Possible overload variants:
+ src/trio/_tests/test_subprocess.py:370: note:     def run_process(command: str | bytes | PathLike[str] | PathLike[bytes], *, task_status: TaskStatus[Process] = ..., stdin: bytes | bytearray | memoryview[int] | int | HasFileno | None = ..., capture_stdout: bool = ..., capture_stderr: bool = ..., check: bool = ..., deliver_cancel: Callable[[Process], Awaitable[object]] | None = ..., stdout: int | HasFileno | None = ..., stderr: int | HasFileno | None = ..., close_fds: bool = ..., shell: Literal[True], cwd: str | bytes | PathLike[str] | PathLike[bytes] | None = ..., env: Mapping[str, str] | None = ..., preexec_fn: Callable[[], object] | None = ..., restore_signals: bool = ..., start_new_session: bool = ..., pass_fds: Sequence[int] = ...) -> Coroutine[Any, Any, CompletedProcess[bytes]]
+ src/trio/_tests/test_subprocess.py:370: note:     def run_process(command: Sequence[str | bytes | PathLike[str] | PathLike[bytes]], *, task_status: TaskStatus[Process] = ..., stdin: bytes | bytearray | memoryview[int] | int | HasFileno | None = ..., capture_stdout: bool = ..., capture_stderr: bool = ..., check: bool = ..., deliver_cancel: Callable[[Process], Awaitable[None]] | None = ..., stdout: int | HasFileno | None = ..., stderr: int | HasFileno | None = ..., close_fds: bool = ..., shell: bool = ..., cwd: str | bytes | PathLike[str] | PathLike[bytes] | None = ..., env: Mapping[str, str] | None = ..., preexec_fn: Callable[[], object] | None = ..., restore_signals: bool = ..., start_new_session: bool = ..., pass_fds: Sequence[int] = ...) -> Coroutine[Any, Any, CompletedProcess[bytes]]
+ src/trio/_tests/test_subprocess.py:468: error: Item "None" of "SendStream | None" has no attribute "aclose"  [union-attr]
+ src/trio/_tests/test_subprocess.py:486: error: Item "None" of "SendStream | None" has no attribute "send_all"  [union-attr]
+ src/trio/_tests/test_subprocess.py:487: error: Item "None" of "SendStream | None" has no attribute "aclose"  [union-attr]
+ src/trio/_tests/test_ssl.py:932: error: "None" not callable  [misc]
+ src/trio/_tests/test_socket.py:353: error: "SocketType" has no attribute "share"  [attr-defined]
+ src/trio/_tests/test_socket.py:354: error: Module has no attribute "fromshare"  [attr-defined]

pandera (https://github.com/pandera-dev/pandera)
+ tests/core/test_schema_components.py:476: error: "Iterable[Any]" has no attribute "tolist"  [attr-defined]

rich (https://github.com/Textualize/rich)
+ rich/_windows.py:56: error: Module has no attribute "getwindowsversion"  [attr-defined]

manticore (https://github.com/trailofbits/manticore)
+ manticore/wasm/types.py:56: error: Unused "type: ignore" comment  [unused-ignore]
+ manticore/native/cpu/abstractcpu.py:693: error: Incompatible types in assignment (expression has type "bool", variable has type "Never")  [assignment]
+ manticore/native/cpu/abstractcpu.py:695: error: Incompatible types in assignment (expression has type "int", variable has type "Never")  [assignment]

pandas (https://github.com/pandas-dev/pandas)
+ pandas/core/dtypes/dtypes.py:480: error: Incompatible types in assignment (expression has type "dtype[Any] | ExtensionDtype", variable has type "str")  [assignment]
+ pandas/core/arrays/categorical.py:453: error: Item "ExtensionArray" of "ExtensionArray | ndarray[Any, Any]" has no attribute "_pa_array"  [union-attr]
+ pandas/core/arrays/categorical.py:453: error: Item "ndarray[Any, Any]" of "ExtensionArray | ndarray[Any, Any]" has no attribute "_pa_array"  [union-attr]
+ pandas/io/pytables.py:2077: error: Value of type "None" is not indexable  [index]
+ pandas/core/generic.py:4656: error: "ndarray[tuple[int, ...], dtype[numpy.bool[builtins.bool]]]" has no attribute "to_numpy"  [attr-defined]
+ pandas/core/frame.py:11564: error: Item "ndarray[Any, Any]" of "ExtensionArray | ndarray[Any, Any]" has no attribute "_reduce"  [union-attr]
+ pandas/core/window/ewm.py:1069: error: Value of type "None" is not indexable  [index]
+ pandas/core/tools/datetimes.py:1056: error: Incompatible types in assignment (expression has type "bool", variable has type "Timestamp | NaTType | Series | Index")  [assignment]
+ pandas/core/internals/managers.py:234: error: "BaseBlockManager" has no attribute "_rebuild_blknos_and_blklocs"  [attr-defined]
+ pandas/core/internals/managers.py:245: error: "BaseBlockManager" has no attribute "_rebuild_blknos_and_blklocs"  [attr-defined]
+ pandas/core/reshape/reshape.py:495: error: Incompatible types in assignment (expression has type "Index", variable has type "Never")  [assignment]
+ pandas/core/reshape/reshape.py:501: error: Generator has incompatible item type "signedinteger[_32Bit | _64Bit]"; expected "ndarray[tuple[int, ...], dtype[signedinteger[_32Bit | _64Bit]]]"  [misc]
+ pandas/core/reshape/reshape.py:508: error: Incompatible types in assignment (expression has type "MultiIndex", variable has type "Never")  [assignment]
+ pandas/core/reshape/reshape.py:966: error: Incompatible types in assignment (expression has type "list[Any]", variable has type "FrozenList")  [assignment]
+ pandas/core/reshape/reshape.py:967: error: Incompatible types in assignment (expression has type "list[ndarray[Any, Any]]", variable has type "FrozenList")  [assignment]
- pandas/io/formats/style.py:1903: error: "Never" has no attribute "shape"  [attr-defined]
- pandas/io/formats/style.py:1906: error: "Never" has no attribute "shape"  [attr-defined]

ignite (https://github.com/pytorch/ignite)
+ ignite/engine/engine.py:246: error: Argument 1 to "append" of "list" has incompatible type "list[str] | list[EventEnum]"; expected "EventEnum"  [arg-type]
+ ignite/engine/engine.py:248: error: Invalid index type "list[str] | list[EventEnum]" for "dict[str | Events | CallableEventWithFilter, str]"; expected type "str | Events | CallableEventWithFilter"  [index]
+ ignite/handlers/param_scheduler.py:1179: error: Argument 1 to "ConcatScheduler" has incompatible type "list[ParamScheduler | ParamGroupScheduler | Any]"; expected "list[ParamScheduler]"  [arg-type]
+ ignite/handlers/param_scheduler.py:1188: error: Argument "schedulers" to "simulate_values" of "ConcatScheduler" has incompatible type "list[ParamScheduler | ParamGroupScheduler | Any]"; expected "list[ParamScheduler]"  [arg-type]
+ ignite/handlers/lr_finder.py:103: error: Unsupported operand types for * ("int" and "None")  [operator]
+ ignite/handlers/lr_finder.py:103: error: Unsupported operand types for * ("None" and "int")  [operator]
+ ignite/handlers/lr_finder.py:103: error: Unsupported left operand type for * ("None")  [operator]
+ ignite/handlers/lr_finder.py:103: note: Both left and right operands are unions

mitmproxy (https://github.com/mitmproxy/mitmproxy)
+ mitmproxy/contentviews/__init__.py:201: error: "None" not callable  [misc]

kornia (https://github.com/kornia/kornia)
+ kornia/feature/lightglue.py:580: error: "None" has no attribute "__iter__" (not iterable)  [attr-defined]
+ kornia/contrib/models/sam/model.py:212: error: "SamConfig" has no attribute "num_heads"  [attr-defined]

PyGithub (https://github.com/PyGithub/PyGithub)
- github/GithubRetry.py:202: error: Unused "type: ignore" comment  [unused-ignore]
+ github/Team.py:305: error: Incompatible types in assignment (expression has type "str", variable has type "Repository")  [assignment]

werkzeug (https://github.com/pallets/werkzeug)
+ src/werkzeug/middleware/shared_data.py:139: error: Cannot assign to a method  [method-assign]
+ src/werkzeug/middleware/shared_data.py:139: error: Incompatible types in assignment (expression has type "Callable[[Arg(str, 'x')], bool]", variable has type "Callable[[Arg(str, 'filename')], bool]")  [assignment]
+ tests/test_wrappers.py:729: error: Incompatible types in assignment (expression has type "str", variable has type "int")  [assignment]
+ tests/test_wrappers.py:741: error: Incompatible types in assignment (expression has type "int", variable has type "Optional[timedelta]")  [assignment]
+ tests/test_wrappers.py:981: error: Call to untyped function "generate_items" in typed context  [no-untyped-call]
+ tests/test_wrappers.py:997: error: Argument 1 to "write" of "ResponseStream" has incompatible type "str"; expected "bytes"  [arg-type]
+ tests/test_wrappers.py:998: error: Non-overlapping equality check (left operand type: "tuple[str, str]", right operand type: "list[str]")  [comparison-overlap]
+ tests/test_http.py:141: error: Incompatible types in assignment (expression has type "float", variable has type "Optional[int]")  [assignment]
+ tests/test_http.py:144: error: Incompatible types in assignment (expression has type "float", variable has type "Optional[int]")  [assignment]

mypy (https://github.com/python/mypy)
+ mypyc/ir/pprint.py:231: error: "PrimitiveOp" has no attribute "type_args"  [attr-defined]
+ mypyc/ir/pprint.py:232: error: "PrimitiveOp" has no attribute "type_args"  [attr-defined]

xarray (https://github.com/pydata/xarray)
+ xarray/core/npcompat.py: note: In function "isdtype":
+ xarray/core/npcompat.py:73: error: Argument 2 to "isinstance" has incompatible type "set[type | type[float64]]"; expected "_ClassInfo"  [arg-type]
+ xarray/core/variable.py:899: error: Unused "type: ignore" comment  [unused-ignore]
+ xarray/core/variable.py:901: error: Unused "type: ignore" comment  [unused-ignore]
+ xarray/core/variable.py: note: In member "_pad_options_dim_to_index" of class "Variable":
+ xarray/core/variable.py:1118: error: Unsupported target for indexed assignment ("Mapping[Any, int | float | tuple[int, int] | tuple[float, float]]")  [index]
+ xarray/core/variable.py: note: At top level:
+ xarray/core/variable.py:2785: error: Unused "type: ignore" comment  [unused-ignore]
+ xarray/core/variable.py:2787: error: Unused "type: ignore" comment  [unused-ignore]
- xarray/core/computation.py: note: In function "apply_variable_ufunc":
- xarray/core/computation.py:848: error: "Never" has no attribute "ndim"  [attr-defined]
- xarray/core/computation.py:851: error: "Never" has no attribute "ndim"  [attr-defined]
+ xarray/coding/cftime_offsets.py: note: In function "date_range_like":
+ xarray/coding/cftime_offsets.py:1588: error: Left operand of "and" is always true  [redundant-expr]
+ xarray/core/dataset.py: note: In member "transpose" of class "Dataset":
+ xarray/core/dataset.py:6173: error: If condition is always true  [redundant-expr]
+ xarray/core/dataset.py: note: At top level:
+ xarray/core/dataarray.py: note: In member "to_pandas" of class "DataArray":
+ xarray/core/dataarray.py:3921: error: Incompatible types in assignment (expression has type "ndarray[Any, Any]", variable has type "Never")  [assignment]
+ xarray/core/dataarray.py: note: At top level:

steam.py (https://github.com/Gobot1234/steam.py)
+ steam/tag.py:117: error: Yield value expected  [misc]
+ steam/abc.py:992: error: Yield value expected  [misc]
+ steam/ext/tf2/backpack.py:301: error: "BackpackItem[OwnerT]" has no attribute "elevated"  [attr-defined]
+ steam/ext/tf2/backpack.py:304: error: "BackpackItem[OwnerT]" has no attribute "killstreak"  [attr-defined]
+ steam/ext/tf2/backpack.py:305: error: "BackpackItem[OwnerT]" has no attribute "killstreak"  [attr-defined]
+ steam/ext/tf2/backpack.py:310: error: "BackpackItem[OwnerT]" has no attribute "festivized"; maybe "is_festivized"?  [attr-defined]
+ steam/ext/tf2/backpack.py:313: error: "BackpackItem[OwnerT]" has no attribute "craft_number"  [attr-defined]
+ steam/ext/tf2/backpack.py:314: error: "BackpackItem[OwnerT]" has no attribute "selfNumber"  [attr-defined]
+ steam/ext/tf2/backpack.py:316: error: "BackpackItem[OwnerT]" has no attribute "crate_number"  [attr-defined]
+ steam/ext/tf2/backpack.py:317: error: "BackpackItem[OwnerT]" has no attribute "selfNumber"  [attr-defined]
+ steam/ext/tf2/backpack.py:343: error: Incompatible return value type (got "BackpackItem[OwnerT]", expected "BackpackItem[None]")  [return-value]

Expression (https://github.com/cognitedata/Expression)
+ expression/core/result.py:267: error: Incompatible types in "yield" (actual type "None", expected type "_TSourceOut")  [misc]
+ expression/core/option.py:308: error: Incompatible types in "yield" (actual type "None", expected type "_TSourceOut")  [misc]
+ README.py:629: error: Incompatible types in assignment (expression has type "range", variable has type "Seq[int]")  [assignment]
+ tests/test_seq_builder.py:186: error: Yield value expected  [misc]
+ tests/test_result_builder.py:221: error: Yield value expected  [misc]
+ tests/test_option_builder.py:218: error: Yield value expected  [misc]

streamlit (https://github.com/streamlit/streamlit)
+ lib/streamlit/type_util.py: note: In function "to_bytes":
+ lib/streamlit/type_util.py:167:26: error: If x = b'abc' then f"{x}" or "{}".format(x) produces "b'abc'", not "abc". If this is desired behavior, use f"{x!r}" or "{!r}".format(x). Otherwise, decode the bytes  [str-bytes-safe]
+ lib/tests/streamlit/watcher/local_sources_watcher_test.py:263:17: error: Module "streamlit.watcher.local_sources_watcher" does not explicitly export attribute "get_default_path_watcher_class"  [attr-defined]
+ lib/tests/streamlit/stop_test.py:25:16: error: Item "None" of "Optional[ScriptRequests]" has no attribute "_state"  [union-attr]

poetry (https://github.com/python-poetry/poetry)
+ src/poetry/utils/helpers.py:307: error: Module has no attribute "OpenKey"  [attr-defined]
+ src/poetry/utils/helpers.py:308: error: Module has no attribute "HKEY_CURRENT_USER"  [attr-defined]
+ src/poetry/utils/helpers.py:311: error: Module has no attribute "QueryValueEx"  [attr-defined]
+ src/poetry/utils/helpers.py:331: error: Module has no attribute "windll"  [attr-defined]
+ src/poetry/utils/helpers.py:342: error: Module has no attribute "windll"  [attr-defined]

urllib3 (https://github.com/urllib3/urllib3)
+ src/urllib3/util/ssl_.py:271: error: Argument 1 to "get" of "dict" has incompatible type "int | None"; expected "int"  [arg-type]
+ src/urllib3/util/ssl_.py:274: error: Argument 1 to "get" of "dict" has incompatible type "int | None"; expected "int"  [arg-type]
+ src/urllib3/util/ssl_.py:288: error: "None" not callable  [misc]
+ src/urllib3/util/ssl_.py:351: error: Returning Any from function declared to return "SSLContext"  [no-any-return]
+ src/urllib3/util/ssl_.py:501: error: "None" has no attribute "_validate_ssl_context_for_tls_in_tls"  [attr-defined]
+ src/urllib3/util/ssl_.py:502: error: Returning Any from function declared to return "SSLSocket | SSLTransport"  [no-any-return]
+ src/urllib3/util/ssl_.py:502: error: "None" not callable  [misc]
+ src/urllib3/contrib/emscripten/response.py:192: error: "None" has no attribute "_put_conn"  [attr-defined]
+ src/urllib3/contrib/emscripten/fetch.py:400: error: Argument 1 to "len" has incompatible type "Buffer"; expected "Sized"  [arg-type]
+ src/urllib3/contrib/emscripten/fetch.py:400: error: Argument 1 to "len" has incompatible type "None"; expected "Sized"  [arg-type]
+ src/urllib3/contrib/emscripten/fetch.py:402: error: Unsupported target for indexed assignment ("Buffer")  [index]
+ src/urllib3/contrib/emscripten/fetch.py:402: error: Value of type "None" is not indexable  [index]
+ src/urllib3/contrib/emscripten/fetch.py:406: error: Argument 1 to "len" has incompatible type "None"; expected "Sized"  [arg-type]
+ test/test_response.py:647: error: Incompatible types in assignment (expression has type "int", variable has type "HTTPResponse | None")  [assignment]

aiohttp (https://github.com/aio-libs/aiohttp)
+ aiohttp/client_exceptions.py:339:19: error: Incompatible types in assignment (expression has type "tuple[Never, ...]", variable has type "tuple[type[SSLCertVerificationError]]")  [assignment]
+ aiohttp/client_exceptions.py:339:19: note: Error code "assignment" not covered by "type: ignore" comment
+ aiohttp/client_exceptions.py:340:25: error: Incompatible types in assignment (expression has type "tuple[type[ClientSSLError], type[ValueError]]", variable has type "tuple[type[ClientSSLError], type[SSLCertVerificationError]]")  [assignment]
+ aiohttp/client_exceptions.py:345:18: error: Incompatible types in assignment (expression has type "tuple[Never, ...]", variable has type "tuple[type[SSLError]]")  [assignment]
+ aiohttp/client_exceptions.py:346:23: error: Incompatible types in assignment (expression has type "tuple[type[ClientSSLError]]", variable has type "tuple[type[ClientSSLError], type[SSLError]]")  [assignment]
+ aiohttp/cookiejar.py:473:13: error: Incompatible types in "yield" (actual type "None", expected type "Morsel[str]")  [misc]
+ aiohttp/cookiejar.py:473:13: note: Error code "misc" not covered by "type: ignore" comment
+ aiohttp/multipart.py:319:32: error: Argument 1 to "decode" of "BodyPartReader" has incompatible type "bytearray"; expected "bytes"  [arg-type]
+ aiohttp/multipart.py:320:16: error: Incompatible return value type (got "bytearray", expected "bytes")  [return-value]
+ aiohttp/connector.py:779:16: error: Incompatible return value type (got "None", expected "SSLContext")  [return-value]
+ aiohttp/connector.py:779:16: note: Error code "return-value" not covered by "type: ignore" comment
+ aiohttp/client_reqrep.py:172:25: error: Incompatible types in assignment (expression has type "tuple[type[bool]]", variable has type "tuple[type[SSLContext], type[bool], type[Fingerprint]]")  [assignment]
+ aiohttp/client_reqrep.py:172:25: note: Error code "assignment" not covered by "type: ignore" comment

spark (https://github.com/apache/spark)
+ python/pyspark/core/context.py:818: error: Unused "type: ignore" comment  [unused-ignore]
+ python/pyspark/core/context.py:819: error: Unused "type: ignore" comment  [unused-ignore]
+ python/pyspark/sql/types.py:1301: error: Incompatible return value type (got "StructType", expected "StructField")  [return-value]
+ python/pyspark/sql/types.py:1301: error: Argument 1 to "StructType" has incompatible type "StructField"; expected "list[StructField] | None"  [arg-type]
+ python/pyspark/sql/types.py:1479: error: Return value expected  [return-value]
+ python/pyspark/sql/types.py:1523: error: Return value expected  [return-value]
+ python/pyspark/sql/readwriter.py:845: error: Function is missing a type annotation  [no-untyped-def]
+ python/pyspark/sql/readwriter.py:854: error: Incompatible types in assignment (expression has type "bool", variable has type "Never")  [assignment]
+ python/pyspark/sql/readwriter.py:855: error: Item "None" of "Any | None" has no attribute "BytesToString"  [union-attr]
+ python/pyspark/sql/readwriter.py:861: error: Item "None" of "Any | None" has no attribute "Encoders"  [union-attr]
+ python/pyspark/sql/streaming/state.py:224: error: Incompatible types in assignment (expression has type "float", variable has type "int")  [assignment]
+ python/pyspark/sql/pandas/conversion.py:712: error: List comprehension has incompatible type List[TimestampType | None]; expected List[DataType]  [misc]
+ python/pyspark/sql/pandas/conversion.py:715: error: PandasDataFrameLike? has no attribute "dtypes"  [attr-defined]
+ python/pyspark/sql/session.py:1538: error: Incompatible types in assignment (expression has type "list[Never]", variable has type "AtomicType | StructType | str | None")  [assignment]
+ python/pyspark/sql/classic/dataframe.py:1609: error: "tuple[dict[str, Column]]" has no attribute "keys"  [attr-defined]
+ python/pyspark/sql/classic/dataframe.py:1610: error: "tuple[dict[str, Column]]" has no attribute "values"  [attr-defined]
+ python/pyspark/pandas/generic.py:788: error: Need type annotation for "new_name"  [var-annotated]
+ python/pyspark/sql/connect/dataframe.py:885: error: "tuple[dict[str, Column]]" has no attribute "items"  [attr-defined]
+ python/pyspark/sql/connect/client/core.py:1783: error: Unexpected keyword argument "message_paramters" for "PySparkValueError"; did you mean "messageParameters"?  [call-arg]
+ python/pyspark/errors/exceptions/base.py:35: note: "PySparkValueError" defined here
+ python/pyspark/sql/worker/write_into_data_source.py:208: error: Incompatible types in assignment (expression has type "WriterCommitMessage", variable has type "Never")  [assignment]
+ python/pyspark/streaming/context.py:390: error: Argument 1 to "parallelize" of "SparkContext" has incompatible type "RDD[T]"; expected "Iterable[T]"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:286: error: Argument 1 to "session" of "BaseReadWrite" has incompatible type "pyspark.sql.connect.session.SparkSession"; expected "pyspark.sql.session.SparkSession"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:287: error: Incompatible return value type (got "Pipeline", expected "RL")  [return-value]
+ python/pyspark/ml/connect/readwrite.py:293: error: Argument 1 to "session" of "BaseReadWrite" has incompatible type "pyspark.sql.connect.session.SparkSession"; expected "pyspark.sql.session.SparkSession"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:294: error: Incompatible return value type (got "PipelineModel", expected "RL")  [return-value]
+ python/pyspark/ml/connect/readwrite.py:300: error: Argument 1 to "session" of "BaseReadWrite" has incompatible type "pyspark.sql.connect.session.SparkSession"; expected "pyspark.sql.session.SparkSession"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:301: error: Incompatible return value type (got "CrossValidator", expected "RL")  [return-value]
+ python/pyspark/ml/connect/readwrite.py:306: error: Argument 1 to "CrossValidatorModelReader" has incompatible type "type[CrossValidator]"; expected "type[CrossValidatorModel]"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:307: error: Argument 1 to "session" of "BaseReadWrite" has incompatible type "pyspark.sql.connect.session.SparkSession"; expected "pyspark.sql.session.SparkSession"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:308: error: Incompatible return value type (got "CrossValidatorModel", expected "RL")  [return-value]
+ python/pyspark/ml/connect/readwrite.py:314: error: Argument 1 to "session" of "BaseReadWrite" has incompatible type "pyspark.sql.connect.session.SparkSession"; expected "pyspark.sql.session.SparkSession"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:315: error: Incompatible return value type (got "TrainValidationSplit", expected "RL")  [return-value]
+ python/pyspark/ml/connect/readwrite.py:320: error: Incompatible types in assignment (expression has type "TrainValidationSplitModelReader", variable has type "TrainValidationSplitReader")  [assignment]
+ python/pyspark/ml/connect/readwrite.py:321: error: Argument 1 to "session" of "BaseReadWrite" has incompatible type "pyspark.sql.connect.session.SparkSession"; expected "pyspark.sql.session.SparkSession"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:322: error: Incompatible return value type (got "TrainValidationSplit", expected "RL")  [return-value]
+ python/pyspark/ml/connect/readwrite.py:328: error: Argument 1 to "session" of "BaseReadWrite" has incompatible type "pyspark.sql.connect.session.SparkSession"; expected "pyspark.sql.session.SparkSession"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:329: error: Incompatible return value type (got "OneVsRest[Any]", expected "RL")  [return-value]
+ python/pyspark/ml/connect/readwrite.py:335: error: Argument 1 to "session" of "BaseReadWrite" has incompatible type "pyspark.sql.connect.session.SparkSession"; expected "pyspark.sql.session.SparkSession"  [arg-type]
+ python/pyspark/ml/connect/readwrite.py:336: error: Incompatible return value type (got "OneVsRestModel", expected "RL")  [return-value]
+ python/pyspark/ml/connect/readwrite.py:356: error: Incompatible types in assignment (expression has type "PowerIterationClustering", variable has type "Never")  [assignment]
+ python/pyspark/ml/connect/readwrite.py:360: error: Unused "type: ignore" comment  [unused-ignore]
+ python/pyspark/mllib/linalg/__init__.py:1104: error: Incompatible return value type (got "SparseVector", expected "DenseVector")  [return-value]

anyio (https://github.com/agronholm/anyio)
+ src/anyio/to_interpreter.py:189: error: Argument 2 to "call" of "Worker" has incompatible type "tuple[*PosArgsT]"; expected "tuple[Any]"  [arg-type]

psycopg (https://github.com/psycopg/psycopg)
+ psycopg/psycopg/_conninfo_attempts_async.py:106: error: Incompatible types in assignment (expression has type "list[tuple[AddressFamily, SocketKind, int, str, tuple[str, int] | tuple[str, int, int, int] | tuple[int, bytes]]]", variable has type "list[tuple[AddressFamily, SocketKind, int, str, tuple[str, int] | tuple[str, int, int, int]]]")  [assignment]
+ psycopg/psycopg/connection_async.py:39: error: Incompatible import of "Lock" (imported name has type "type[lock]", local name has type "type[Lock]")  [assignment]
+ psycopg/psycopg/connection_async.py:56: error: Incompatible types in assignment (expression has type "type[KeyboardInterrupt]", variable has type "tuple[type[CancelledError], type[KeyboardInterrupt]]")  [assignment]
+ psycopg/psycopg/connection_async.py:447: error: Value of type "Coroutine[Any, Any, None]" must be used  [unused-coroutine]
+ psycopg/psycopg/connection_async.py:447: note: Are you missing an await?
+ psycopg/psycopg/connection_async.py:458: error: Value of type "Coroutine[Any, Any, None]" must be used  [unused-coroutine]
+ psycopg/psycopg/connection_async.py:458: note: Are you missing an await?
+ psycopg/psycopg/connection_async.py:469: error: Value of type "Coroutine[Any, Any, None]" must be used  [unused-coroutine]
+ psycopg/psycopg/connection_async.py:469: note: Are you missing an await?
+ psycopg/psycopg/connection_async.py:480: error: Value of type "Coroutine[Any, Any, None]" must be used  [unused-coroutine]
+ psycopg/psycopg/connection_async.py:480: note: Are you missing an await?
+ tests/pq/test_pgconn.py:45: error: If x = b'abc' then f"{x}" or "{}".format(x) produces "b'abc'", not "abc". If this is desired behavior, use f"{x!r}" or "{!r}".format(x). Otherwise, decode the bytes  [str-bytes-safe]
+ tests/pool/test_sched_async.py:153: error: Incompatible types in assignment (expression has type "tuple[Any]", variable has type "tuple[()]")  [assignment]
+ psycopg_pool/psycopg_pool/pool_async.py:120: error: Expected iterable as variadic argument  [misc]
+ psycopg_pool/psycopg_pool/pool_async.py:120: error: Value of type "Coroutine[Any, Any, None]" must be used  [unused-coroutine]
+ psycopg_pool/psycopg_pool/pool_async.py:120: note: Are you missing an await?
+ psycopg_pool/psycopg_pool/pool_async.py:591: error: Value of type "Coroutine[Any, Any, AsyncCursor[Any]]" must be used  [unused-coroutine]
+ psycopg_pool/psycopg_pool/pool_async.py:591: note: Are you missing an await?
+ tests/pool/test_pool_common_async.py:71: error: Incompatible types in assignment (expression has type "type[DeprecationWarning]", variable has type "type[RuntimeWarning]")  [assignment]

jinja (https://github.com/pallets/jinja)
+ src/jinja2/runtime.py:903: error: Statement is unreachable  [unreachable]

dulwich (https://github.com/dulwich/dulwich)
+ dulwich/refs.py:804: error: Unsupported right operand type for in ("None")  [operator]
+ dulwich/refs.py:807: error: "None" has no attribute "__delitem__"  [attr-defined]
+ dulwich/refs.py:809: error: "None" has no attribute "__delitem__"  [attr-defined]

antidote (https://github.com/Finistere/antidote)
+ tests/lib/injectable/test_injectable.py:121: error: Missing positional argument "x" in call to "method" of "MyService"  [call-arg]

sphinx (https://github.com/sphinx-doc/sphinx)
+ sphinx/util/osutil.py: note: In function "_relative_path":
+ sphinx/util/osutil.py:191:12: error: Unexpected keyword argument "walk_up" for "relative_to" of "PurePath"  [call-arg]
+ note: "relative_to" of "PurePath" defined here
+ sphinx/transforms/__init__.py: note: In member "apply_transforms" of class "SphinxTransformer":
+ sphinx/transforms/__init__.py:103:33: error: Incompatible types in assignment (expression has type "Node", variable has type "document")  [assignment]

pandas-stubs (https://github.com/pandas-dev/pandas-stubs)
+ tests/test_frame.py:3808: error: All overload variants of "select_dtypes" of "DataFrame" require at least one argument  [call-overload]
+ tests/test_frame.py:3808: note: Possible overload variants:
+ tests/test_frame.py:3808: note:     def select_dtypes(self, include: Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_], exclude: Literal['number', 'datetime64', 'datetime', 'integer', 'timedelta', 'timedelta64', 'datetimetz', 'datetime64[ns]'] | Literal['bool', 'boolean', '?', 'b1', 'bool_', 'bool[pyarrow]', 'boolean[pyarrow]'] | type[builtins.bool] | BooleanDtype | type[numpy.bool[builtins.bool]] | Literal['int', 'Int8', 'Int16', 'Int32', 'Int64', 'b', 'i1', 'int8', 'byte', 'h', 'i2', 'int16', 'short', 'i', 'i4', 'int32', 'intc', 'l', 'i8', 'int64', 'int_', 'long', 'q', 'longlong', 'p', 'intp', 'int8[pyarrow]', 'int16[pyarrow]', 'int32[pyarrow]', 'int64[pyarrow]'] | type[int] | Int8Dtype | Int16Dtype | Int32Dtype | Int64Dtype | <6 more items> | Literal['UInt8', 'UInt16', 'UInt32', 'UInt64', 'B', 'u1', 'uint8', 'ubyte', 'H', 'u2', 'uint16', 'ushort', 'I', 'u4', 'uint32', 'uintc', 'L', 'u8', 'uint', 'ulong', 'uint64', 'Q', 'ulonglong', 'P', 'uintp', 'uint8[pyarrow]', 'uint16[pyarrow]', 'uint32[pyarrow]', 'uint64[pyarrow]'] | UInt8Dtype | UInt16Dtype | UInt32Dtype | UInt64Dtype | type[unsignedinteger[_8Bit]] | type[unsignedinteger[_16Bit]] | type[unsignedinteger[_32Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | type[unsignedinteger[_64Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_] | Literal['bytes', 'S', 'bytes_', 'bytes0', 'string_', 'binary[pyarrow]'] | type[bytes] | type[bytes_] | <8 more items> | list[Literal['number', 'datetime64', 'datetime', 'integer', 'timedelta', 'timedelta64', 'datetimetz', 'datetime64[ns]'] | Literal['bool', 'boolean', '?', 'b1', 'bool_', 'bool[pyarrow]', 'boolean[pyarrow]'] | type[builtins.bool] | BooleanDtype | type[numpy.bool[builtins.bool]] | Literal['int', 'Int8', 'Int16', 'Int32', 'Int64', 'b', 'i1', 'int8', 'byte', 'h', 'i2', 'int16', 'short', 'i', 'i4', 'int32', 'intc', 'l', 'i8', 'int64', 'int_', 'long', 'q', 'longlong', 'p', 'intp', 'int8[pyarrow]', 'int16[pyarrow]', 'int32[pyarrow]', 'int64[pyarrow]'] | type[int] | Int8Dtype | Int16Dtype | Int32Dtype | Int64Dtype | <6 more items> | Literal['UInt8', 'UInt16', 'UInt32', 'UInt64', 'B', 'u1', 'uint8', 'ubyte', 'H', 'u2', 'uint16', 'ushort', 'I', 'u4', 'uint32', 'uintc', 'L', 'u8', 'uint', 'ulong', 'uint64', 'Q', 'ulonglong', 'P', 'uintp', 'uint8[pyarrow]', 'uint16[pyarrow]', 'uint32[pyarrow]', 'uint64[pyarrow]'] | UInt8Dtype | UInt16Dtype | UInt32Dtype | UInt64Dtype | type[unsignedinteger[_8Bit]] | type[unsignedinteger[_16Bit]] | type[unsignedinteger[_32Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | type[unsignedinteger[_64Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_] | Literal['bytes', 'S', 'bytes_', 'bytes0', 'string_', 'binary[pyarrow]'] | type[bytes] | type[bytes_] | <8 more items>] | None = ...) -> Never
+ tests/test_frame.py:3808: note:     def select_dtypes(self, include: Literal['number', 'datetime64', 'datetime', 'integer', 'timedelta', 'timedelta64', 'datetimetz', 'datetime64[ns]'] | Literal['bool', 'boolean', '?', 'b1', 'bool_', 'bool[pyarrow]', 'boolean[pyarrow]'] | type[builtins.bool] | BooleanDtype | type[numpy.bool[builtins.bool]] | Literal['int', 'Int8', 'Int16', 'Int32', 'Int64', 'b', 'i1', 'int8', 'byte', 'h', 'i2', 'int16', 'short', 'i', 'i4', 'int32', 'intc', 'l', 'i8', 'int64', 'int_', 'long', 'q', 'longlong', 'p', 'intp', 'int8[pyarrow]', 'int16[pyarrow]', 'int32[pyarrow]', 'int64[pyarrow]'] | type[int] | Int8Dtype | Int16Dtype | Int32Dtype | Int64Dtype | <6 more items> | Literal['UInt8', 'UInt16', 'UInt32', 'UInt64', 'B', 'u1', 'uint8', 'ubyte', 'H', 'u2', 'uint16', 'ushort', 'I', 'u4', 'uint32', 'uintc', 'L', 'u8', 'uint', 'ulong', 'uint64', 'Q', 'ulonglong', 'P', 'uintp', 'uint8[pyarrow]', 'uint16[pyarrow]', 'uint32[pyarrow]', 'uint64[pyarrow]'] | UInt8Dtype | UInt16Dtype | UInt32Dtype | UInt64Dtype | type[unsignedinteger[_8Bit]] | type[unsignedinteger[_16Bit]] | type[unsignedinteger[_32Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | type[unsignedinteger[_64Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_] | Literal['bytes', 'S', 'bytes_', 'bytes0', 'string_', 'binary[pyarrow]'] | type[bytes] | type[bytes_] | <8 more items> | list[Literal['number', 'datetime64', 'datetime', 'integer', 'timedelta', 'timedelta64', 'datetimetz', 'datetime64[ns]'] | Literal['bool', 'boolean', '?', 'b1', 'bool_', 'bool[pyarrow]', 'boolean[pyarrow]'] | type[builtins.bool] | BooleanDtype | type[numpy.bool[builtins.bool]] | Literal['int', 'Int8', 'Int16', 'Int32', 'Int64', 'b', 'i1', 'int8', 'byte', 'h', 'i2', 'int16', 'short', 'i', 'i4', 'int32', 'intc', 'l', 'i8', 'int64', 'int_', 'long', 'q', 'longlong', 'p', 'intp', 'int8[pyarrow]', 'int16[pyarrow]', 'int32[pyarrow]', 'int64[pyarrow]'] | type[int] | Int8Dtype | Int16Dtype | Int32Dtype | Int64Dtype | <6 more items> | Literal['UInt8', 'UInt16', 'UInt32', 'UInt64', 'B', 'u1', 'uint8', 'ubyte', 'H', 'u2', 'uint16', 'ushort', 'I', 'u4', 'uint32', 'uintc', 'L', 'u8', 'uint', 'ulong', 'uint64', 'Q', 'ulonglong', 'P', 'uintp', 'uint8[pyarrow]', 'uint16[pyarrow]', 'uint32[pyarrow]', 'uint64[pyarrow]'] | UInt8Dtype | UInt16Dtype | UInt32Dtype | UInt64Dtype | type[unsignedinteger[_8Bit]] | type[unsignedinteger[_16Bit]] | type[unsignedinteger[_32Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | type[unsignedinteger[_64Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_] | Literal['bytes', 'S', 'bytes_', 'bytes0', 'string_', 'binary[pyarrow]'] | type[bytes] | type[bytes_] | <8 more items>] | None, exclude: Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_]) -> Never
+ tests/test_frame.py:3808: note:     def select_dtypes(self, exclude: Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_]) -> Never
+ tests/test_frame.py:3808: note:     def select_dtypes(self, include: list[Never], exclude: list[Never]) -> Never
+ tests/test_frame.py:3808: note:     def select_dtypes(self, include: Literal['number', 'datetime64', 'datetime', 'integer', 'timedelta', 'timedelta64', 'datetimetz', 'datetime64[ns]'] | Literal['bool', 'boolean', '?', 'b1', 'bool_', 'bool[pyarrow]', 'boolean[pyarrow]'] | type[builtins.bool] | BooleanDtype | type[numpy.bool[builtins.bool]] | Literal['int', 'Int8', 'Int16', 'Int32', 'Int64', 'b', 'i1', 'int8', 'byte', 'h', 'i2', 'int16', 'short', 'i', 'i4', 'int32', 'intc', 'l', 'i8', 'int64', 'int_', 'long', 'q', 'longlong', 'p', 'intp', 'int8[pyarrow]', 'int16[pyarrow]', 'int32[pyarrow]', 'int64[pyarrow]'] | type[int] | Int8Dtype | Int16Dtype | Int32Dtype | Int64Dtype | <6 more items> | Literal['UInt8', 'UInt16', 'UInt32', 'UInt64', 'B', 'u1', 'uint8', 'ubyte', 'H', 'u2', 'uint16', 'ushort', 'I', 'u4', 'uint32', 'uintc', 'L', 'u8', 'uint', 'ulong', 'uint64', 'Q', 'ulonglong', 'P', 'uintp', 'uint8[pyarrow]', 'uint16[pyarrow]', 'uint32[pyarrow]', 'uint64[pyarrow]'] | UInt8Dtype | UInt16Dtype | UInt32Dtype | UInt64Dtype | type[unsignedinteger[_8Bit]] | type[unsignedinteger[_16Bit]] | type[unsignedinteger[_32Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | type[unsignedinteger[_64Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_] | Literal['bytes', 'S', 'bytes_', 'bytes0', 'string_', 'binary[pyarrow]'] | type[bytes] | type[bytes_] | <8 more items> | list[Literal['number', 'datetime64', 'datetime', 'integer', 'timedelta', 'timedelta64', 'datetimetz', 'datetime64[ns]'] | Literal['bool', 'boolean', '?', 'b1', 'bool_', 'bool[pyarrow]', 'boolean[pyarrow]'] | type[builtins.bool] | BooleanDtype | type[numpy.bool[builtins.bool]] | Literal['int', 'Int8', 'Int16', 'Int32', 'Int64', 'b', 'i1', 'int8', 'byte', 'h', 'i2', 'int16', 'short', 'i', 'i4', 'int32', 'intc', 'l', 'i8', 'int64', 'int_', 'long', 'q', 'longlong', 'p', 'intp', 'int8[pyarrow]', 'int16[pyarrow]', 'int32[pyarrow]', 'int64[pyarrow]'] | type[int] | Int8Dtype | Int16Dtype | Int32Dtype | Int64Dtype | <6 more items> | Literal['UInt8', 'UInt16', 'UInt32', 'UInt64', 'B', 'u1', 'uint8', 'ubyte', 'H', 'u2', 'uint16', 'ushort', 'I', 'u4', 'uint32', 'uintc', 'L', 'u8', 'uint', 'ulong', 'uint64', 'Q', 'ulonglong', 'P', 'uintp', 'uint8[pyarrow]', 'uint16[pyarrow]', 'uint32[pyarrow]', 'uint64[pyarrow]'] | UInt8Dtype | UInt16Dtype | UInt32Dtype | UInt64Dtype | type[unsignedinteger[_8Bit]] | type[unsignedinteger[_16Bit]] | type[unsignedinteger[_32Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | type[unsignedinteger[_64Bit]] | type[unsignedinteger[_32Bit | _64Bit]] | Literal['str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]'] | type[str] | StringDtype | type[str_] | Literal['bytes', 'S', 'bytes_', 'bytes0', 'string_', 'binary[pyarrow]'] | type[bytes] | type[bytes_] | <8 more items>], exclude: Literal['bool', 'boolean', '?', 'b1', 'bool_', 'bool[pyarrow]', 'boolean[pyarrow]', 'int', 'Int8', 'Int16', 'Int32', 'Int64', 'b', 'i1', 'int8', 'byte', 'h', 'i2', 'int16', 'short', 'i', 'i4', 'int32', 'intc', 'l', 'i8', 'int64', 'int_', 'long', 'q', 'longlong', 'p', 'intp', 'int8[pyarrow]', 'int16[pyarrow]', 'int32[pyarrow]', 'int64[pyarrow]', 'UInt8', 'UInt16', 'UInt32', 'UInt64', 'B', 'u1', 'uint8', 'ubyte', 'H', 'u2', 'uint16', 'ushort', 'I', 'u4', 'uint32', 'uintc', 'L', 'u8', 'uint', 'ulong', 'uint64', 'Q', 'ulonglong', 'P', 'uintp', 'uint8[pyarrow]', 'uint16[pyarrow]', 'uint32[pyarrow]', 'uint64[pyarrow]', 'str', 'string', 'U', 'str_', 'str0', 'unicode', 'unicode_', 'string[pyarrow]', 'bytes', 'S', 'bytes_', 'bytes0', 'string_', 'binary[pyarrow]', 'float', 'Float32', 'Float64', 'e', 'f2', '<f2', 'float16', 'half', 'f', 'f4', 'float32', 'single', 'd', 'f8', 'float64', 'double', 'float_', 'g', 'f16', 'float128', 'longdouble', 'longfloat', 'float[pyarrow]', 'double[pyarrow]', 'float16[pyarrow]', 'float32[pyarrow]', 'float64[pyarrow]', 'complex', 'F', 'c8', 'complex64', 'csingle', 'singlecomplex', 'D', 'c16', 'complex128', 'cdouble', 'cfloat', 'complex_', 'G', 'c32', 'complex256', 'clongdouble', 'clongfloat', 'longcomplex', 'timedelta64[Y]', 'timedelta64[M]', 'timedelta64[W]', 'timedelta64[D]', 'timedelta64[h]', 'timedelta64[m]', 'timedelta64[s]', 'timedelta64[ms]', 'timedelta64[us]', 'timedelta64[μs]', 'timedelta64[ns]', 'timedelta64[ps]', 'timedelta64[fs]', 'timedelta64[as]', 'm8[Y]', 'm8[M]', 'm8[W]', 'm8[D]', 'm8[h]', 'm8[m]', 'm8[s]', 'm8[ms]', 'm8[us]', 'm8[μs]', 'm8[ns]', 'm8[ps]', 'm8[fs]', 'm8[as]', '<m8[Y]', '<m8[M]', '<m8[W]', '<m8[D]', '<m8[h]', '<m8[m]', '<m8[s]', '<m8[ms]', '<m8[us]', '<m8[μs]', '<m8[ns]', '<m8[ps]', '<m8[fs]', '<m8[as]', 'duration[s][pyarrow]', 'duration[ms][pyarrow]', 'duration[us][pyarrow]', 'duration[ns][pyarrow]', 'datetime64[Y]', 'datetime64[M]', 'datetime64[W]', 'datetime64[D]', 'datetime64[h]', 'datetime64[m]', 'datetime64[s]', 'datetime64[ms]', 'datetime64[us]', 'datetime64[μs]', 'datetime64[ns]', 'datetime64[ps]', 'datetime64[fs]', 'datetime64[as]', 'M8[Y]', 'M8[M]', 'M8[W]', 'M8[D]', 'M8[h]', 'M8[m]', 'M8[s]', 'M8[ms]', 'M8[us]', 'M8[μs]', 'M8[ns]', 'M8[ps]', 'M8[fs]', 'M8[as]', '<M8[Y]', '<M8[M]', '<M8[W]', '<M8[D]', '<M8[h]', '<M8[m]', '<M8[s]', '<M8[ms]', '<M8[us]', '<M8[μs]', '<M8[ns]', '<M8[ps]', '<M8[fs]', '<M8[as]', 'date32[pyarrow]', 'date64[pyarrow]', 'timestamp[s][pyarrow]', 'timestamp[ms][pyarrow]', 'timestamp[us][pyarrow]', 'timestamp[ns][pyarrow]', 'category', 'object', 'O', 'V', 'void', 'void0', 'number', 'datetime64', 'datetime', 'integer', 'timedelta', 'timedelta64', 'datetimetz'] | type[builtins.bool] | BooleanDtype | type[numpy.bool[builtins.bool]] | type[int] | Int8Dtype | <40 more items> | None = ...) -> DataFrame

... (truncated 2 lines) ...

yarl (https://github.com/aio-libs/yarl)
+ yarl/_quoting_py.py:38:20: error: Incompatible return value type (got "None", expected "str")  [return-value]
+ yarl/_quoting_py.py:127:20: error: Incompatible return value type (got "None", expected "str")  [return-value]
+ yarl/_query.py:36:24: error: Argument 1 to "int" has incompatible type "Union[Union[str, int, float], Sequence[Union[str, int, float]]]"; expected "Union[str, Buffer, SupportsInt, SupportsIndex, SupportsTrunc]"  [arg-type]

pydantic (https://github.com/pydantic/pydantic)
+ pydantic/v1/typing.py:228: error: Incompatible return value type (got "GenericAlias", expected "type[Any]")  [return-value]
+ pydantic/v1/main.py:1086: error: Incompatible types in assignment (expression has type "set[str]", variable has type "Never")  [assignment]

websockets (https://github.com/aaugustin/websockets)
+ src/websockets/legacy/protocol.py:1077: error: Argument 1 to "join" of "str" has incompatible type "list[str | bytes]"; expected "Iterable[str]"  [arg-type]
+ src/websockets/legacy/protocol.py:1077: error: Argument 1 to "join" of "bytes" has incompatible type "list[str | bytes]"; expected "Iterable[Buffer]"  [arg-type]

pip (https://github.com/pypa/pip)
+ src/pip/_internal/resolution/legacy/resolver.py:454: error: Argument 2 to "prepare_installed_requirement" of "RequirementPreparer" has incompatible type "str | None"; expected "str"  [arg-type]
+ src/pip/_internal/resolution/legacy/resolver.py:476: error: Item "None" of "Link | None" has no attribute "scheme"  [union-attr]

pwndbg (https://github.com/pwndbg/pwndbg)
+ pwndbg/aglib/dynamic.py: note: In function "r_debug_install_link_map_changed_hook":
+ pwndbg/aglib/dynamic.py:134: error: Unexpected keyword argument "stop_hook" for "break_at" of "Process"  [call-arg]
+ pwndbg/dbg/__init__.py:490: note: "break_at" of "Process" defined here
+ pwndbg/aglib/onegadget.py: note: In function "check_constraint":
+ pwndbg/aglib/onegadget.py:507: error: Argument 1 to "find" has incompatible type "CheckSatResult"; expected "int | Value | None"  [arg-type]

Tanjun (https://github.com/FasterSpeeding/Tanjun)
+ tanjun/_internal/__init__.py:83: error: Returning Any from function declared to return "bool"  [no-any-return]
- tanjun/parsing.py:588: error: "Never" has no attribute "__iter__" (not iterable)  [attr-defined]
- tanjun/parsing.py:1632: error: Statement is unreachable  [unreachable]
- tanjun/parsing.py:1642: error: Statement is unreachable  [unreachable]
- tanjun/dependencies/limiters.py:851: error: "Never" has no attribute "unlock"  [attr-defined]
+ tanjun/dependencies/limiters.py:852: error: Statement is unreachable  [unreachable]
- tanjun/commands/slash.py:820: error: Statement is unreachable  [unreachable]
- tanjun/commands/slash.py:1787: error: Statement is unreachable  [unreachable]
- tanjun/clients.py:2294: error: "Never" has no attribute "__iter__" (not iterable)  [attr-defined]
+ tanjun/clients.py:2295: error: Statement is unreachable  [unreachable]
+ tanjun/annotations.py:1453: error: Incompatible types in assignment (expression has type "type[int]", variable has type "type[float]")  [assignment]
+ tanjun/annotations.py:1455: error: Incompatible types in assignment (expression has type "_IntEnumConverter", variable has type "_FloatEnumConverter")  [assignment]
+ tanjun/annotations.py:1458: error: Incompatible types in assignment (expression has type "type[str]", variable has type "type[float]")  [assignment]

ibis (https://github.com/ibis-project/ibis)
- ibis/common/bases.py:231: error: Need type annotation for "field"  [var-annotated]
+ ibis/util.py:656: error: Need type annotation for "hashable_obj"  [var-annotated]
+ ibis/util.py:660: error: Incompatible types in assignment (expression has type "frozenset[Never]", variable has type "tuple[Any, ...]")  [assignment]
+ ibis/util.py:662: error: Incompatible types in assignment (expression has type "int", variable has type "tuple[Any, ...]")  [assignment]
+ ibis/common/tests/test_grounds_py310.py:45: error: Too many positional patterns for class pattern  [misc]


... (truncated 229 lines) ...```

A5rocks added 10 commits February 19, 2025 15:21

Start type checking unreachable code

be1071e

Except things important enough we marked them before, which include: - `if not typing.TYPE_CHECKING` - platform checks that do not match

Pass self-check

d996918

Hacky fix to narrow unreachable literals

07de5bf

20% of tests

bac268b

25% of tests

2da4b7c

30% of tests

ba9dab2

40% of tests

7c39efa

50% of tests

18642d0

60% of tests

879b274

Pass all tests

c62093e