Add --disallow-str-iteration flag #20577

michaelm-openai · 2026-01-13T16:17:51Z

Fixes #11001

Related to typing python/typing#256

Expected behavior changes under this flag:

str and its subtypes are no longer treated as subtypes of Collection, Iterable, Sequence or protocols that extend them. Assignment and argument passing will be treated as errors.
The builtin iter() method has an additional overload which accepts str. This is the recommended way to iterate over characters when this flag is enabled.
Invalid assignment of str to subtypes of Container, such as Collection will not report a conflict on the __contains__ method, since this introduces noise. It is known that str does not conform to the Container protocol due to its incompatible signature for __contains__ method.

for more information, see https://pre-commit.ci

docs/source/command_line.rst

mypy/checker.py

mypy/subtypes.py

JelleZijlstra · 2026-01-13T16:29:24Z

mypy/typeshed/stdlib/builtins.pyi

    def __getitem__(self, i: int, /) -> _T_co: ...

+@overload
+def iter(object: str, /) -> Iterable[str]: ...


This needs to be in a patch file, or it will be overwritten next time we sync typeshed. Look for similar patch files in the repo (there are a few related to LiteralString).

test-data/unit/check-flags.test

for more information, see https://pre-commit.ci

mypy/checker.py

mypy/messages.py

for more information, see https://pre-commit.ci

michaelm-openai · 2026-01-14T18:38:59Z

I think the apprise diff is expected given that we added a new overload. The full diagnostic is:

apprise/config/base.py:1509: error: No overload variant of "iter" matches argument type "None"  [call-overload]
apprise/config/base.py:1509: note: Possible overload variants:
apprise/config/base.py:1509: note:     def [_SupportsNextT_co: SupportsNext[Any]] iter(SupportsIter[_SupportsNextT_co], /) -> _SupportsNextT_co
apprise/config/base.py:1509: note:     def iter(str, /) -> Iterator[str]
apprise/config/base.py:1509: note:     def [_T] iter(_GetItemIterable[_T], /) -> Iterator[_T]
apprise/config/base.py:1509: note:     def [_T] iter(Callable[[], _T | None], None, /) -> Iterator[_T]
apprise/config/base.py:1509: note:     def [_T] iter(Callable[[], _T], object, /) -> Iterator[_T]

github-actions · 2026-01-14T21:58:34Z

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

beartype (https://github.com/beartype/beartype)
+ beartype/_data/kind/datakindtext.py:18: error: Argument 1 to "frozenset" has incompatible type "str"; expected "Iterable[str]"  [arg-type]

spack (https://github.com/spack/spack)
+ lib/spack/spack/schema/mirrors.py:103: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Sequence[object]"  [dict-item]
+ lib/spack/spack/schema/mirrors.py:107: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Sequence[object]"  [dict-item]
+ lib/spack/spack/llnl/util/filesystem.py:2182: error: Iterating over "str | list[str]" is disallowed  [misc]
+ lib/spack/spack/llnl/util/filesystem.py:2182: note: This is because --disallow-str-iteration is enabled
+ lib/spack/spack/llnl/util/filesystem.py:2340: error: Iterating over "str | list[str]" is disallowed  [misc]
+ lib/spack/spack/llnl/util/filesystem.py:2340: note: This is because --disallow-str-iteration is enabled
+ lib/spack/spack/llnl/util/filesystem.py:2418: error: Iterating over "str | list[str]" is disallowed  [misc]
+ lib/spack/spack/llnl/util/filesystem.py:2418: note: This is because --disallow-str-iteration is enabled
+ lib/spack/spack/version/version_types.py:964: error: Iterating over "str | Iterable[Any]" is disallowed  [misc]
+ lib/spack/spack/version/version_types.py:964: note: This is because --disallow-str-iteration is enabled
+ lib/spack/spack/schema/modules.py:48: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Sequence[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:52: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Sequence[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:56: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:61: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:95: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:100: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:110: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:154: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:159: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:164: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/schema/modules.py:219: error: Dict entry 1 has incompatible type "str": "str"; expected "str": "Collection[str]"  [dict-item]
+ lib/spack/spack/install_test.py:521: error: Argument 1 to "join" of "str" has incompatible type "Any | str"; expected "Iterable[str]"  [arg-type]
+ lib/spack/spack/bootstrap/status.py:88: error: Incompatible types in assignment (expression has type "dict[Sequence[str], str]", variable has type "dict[str | Sequence[str], str]")  [assignment]
+ lib/spack/spack/bootstrap/status.py:88: note: "dict" is invariant -- see https://mypy.readthedocs.io/en/stable/common_issues.html#variance
+ lib/spack/spack/bootstrap/status.py:88: note: Consider using "Mapping" instead, which is covariant in the value type
+ lib/spack/spack/test/spec_yaml.py:330: error: List item 0 has incompatible type "tuple[str, str]"; expected "tuple[str, Collection[str]]"  [list-item]
+ lib/spack/spack/test/spec_yaml.py:331: error: List item 1 has incompatible type "tuple[str, str]"; expected "tuple[str, Collection[str]]"  [list-item]
+ lib/spack/spack/cmd/info.py:151: error: Argument 1 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]

com2ann (https://github.com/ilevkivskyi/com2ann)
+ src/com2ann.py:436: error: Iterating over "str" is disallowed  [misc]
+ src/com2ann.py:436: note: This is because --disallow-str-iteration is enabled
+ src/com2ann.py:633: error: Argument 1 to "enumerate" has incompatible type "str"; expected "Iterable[str]"  [arg-type]

CPython (Argument Clinic) (https://github.com/python/cpython)
+ Tools/clinic/libclinic/codegen.py:161: error: Argument 1 to "join" of "str" has incompatible type "str"; expected "Iterable[str]"  [arg-type]

hydpy (https://github.com/hydpy-dev/hydpy)
+ hydpy/cythons/modelutils.py:2806: error: Iterating over "str" is disallowed  [misc]
+ hydpy/cythons/modelutils.py:2806: note: This is because --disallow-str-iteration is enabled
+ hydpy/core/timetools.py:527: error: Argument 1 to "enumerate" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ hydpy/core/devicetools.py:3153: error: Incompatible types in assignment (expression has type "str | Iterable[str] | None", variable has type "Iterable[str] | None")  [assignment]
+ hydpy/auxs/networktools.py:188: error: Argument 1 to "zip" has incompatible type "RiverBasinNumber"; expected "Iterable[str]"  [arg-type]
+ hydpy/auxs/networktools.py:188: error: Argument 2 to "zip" has incompatible type "RiverBasinNumber"; expected "Iterable[str]"  [arg-type]
+ hydpy/auxs/networktools.py:273: error: Iterating over "RiverBasinNumber" is disallowed  [misc]
+ hydpy/auxs/networktools.py:273: note: This is because --disallow-str-iteration is enabled
+ hydpy/auxs/networktools.py:368: error: Iterating over "RiverBasinNumber" is disallowed  [misc]
+ hydpy/auxs/networktools.py:368: note: This is because --disallow-str-iteration is enabled
+ hydpy/auxs/interptools.py:160: error: Argument 1 to "product" has incompatible type "str | list[str]"; expected "Iterable[str]"  [arg-type]
+ hydpy/auxs/interptools.py:160: error: Argument 2 to "product" has incompatible type "str | list[str]"; expected "Iterable[str]"  [arg-type]

optuna (https://github.com/optuna/optuna)
+ optuna/testing/pytest_storages.py:932: error: Incompatible types in assignment (expression has type "dict[str, Mapping[str, JSONSerializable] | Sequence[JSONSerializable] | int | float | None]", variable has type "dict[str, JSONSerializable]")  [assignment]
+ optuna/testing/pytest_storages.py:932: note: "dict" is invariant -- see https://mypy.readthedocs.io/en/stable/common_issues.html#variance
+ optuna/testing/pytest_storages.py:932: note: Consider using "Mapping" instead, which is covariant in the value type
+ optuna/testing/pytest_storages.py:933: error: Dict entry 0 has incompatible type "str": "str"; expected "str": "Mapping[str, JSONSerializable] | Sequence[JSONSerializable] | int | float | None"  [dict-item]
+ optuna/testing/pytest_storages.py:935: error: List item 0 has incompatible type "str"; expected "Mapping[str, JSONSerializable] | Sequence[JSONSerializable] | int | float | None"  [list-item]
+ optuna/testing/pytest_storages.py:935: error: List item 1 has incompatible type "str"; expected "Mapping[str, JSONSerializable] | Sequence[JSONSerializable] | int | float | None"  [list-item]
+ tests/storages_tests/rdb_tests/test_storage.py:366: error: Argument 2 to "OperationalError" has incompatible type "str"; expected "Sequence[Sequence[Any]] | Sequence[Mapping[str, Any]] | Sequence[Any] | Mapping[str, Any] | None"  [arg-type]
+ tests/visualization_tests/test_hypervolume_history.py:26: error: Iterating over "str" is disallowed  [misc]
+ tests/visualization_tests/test_hypervolume_history.py:26: note: This is because --disallow-str-iteration is enabled
+ tests/visualization_tests/test_hypervolume_history.py:52: error: Argument "directions" to "create_study" has incompatible type "str"; expected "Sequence[str | StudyDirection] | None"  [arg-type]
+ tests/study_tests/test_study.py:177: error: Argument "directions" to "create_study" has incompatible type "str"; expected "Sequence[str | StudyDirection] | None"  [arg-type]
+ optuna/visualization/_parallel_coordinate.py:289: error: Dict entry 0 has incompatible type "str": "str"; expected "str": "Sequence[object]"  [dict-item]
+ optuna/visualization/_parallel_coordinate.py:297: error: Dict entry 0 has incompatible type "str": "str"; expected "str": "Sequence[object]"  [dict-item]

spark (https://github.com/apache/spark)
+ python/pyspark/sql/variant_utils.py:677: error: Iterating over "str" is disallowed  [misc]
+ python/pyspark/sql/variant_utils.py:677: note: This is because --disallow-str-iteration is enabled
+ python/pyspark/sql/classic/dataframe.py:1516: error: Iterating over "str | list[str]" is disallowed  [misc]
+ python/pyspark/sql/classic/dataframe.py:1516: note: This is because --disallow-str-iteration is enabled
+ python/pyspark/pandas/frame.py:7331: error: Argument 1 to "list" has incompatible type "str | list[str] | None"; expected "Iterable[str]"  [arg-type]
+ python/pyspark/pandas/frame.py:7336: error: Argument 1 to "list" has incompatible type "str | list[str] | None"; expected "Iterable[str]"  [arg-type]
+ python/pyspark/sql/connect/dataframe.py:1588: error: Iterating over "str | list[str]" is disallowed  [misc]
+ python/pyspark/sql/connect/dataframe.py:1588: note: This is because --disallow-str-iteration is enabled
+ python/pyspark/sql/connect/dataframe.py:1635: error: Argument 1 to "list" has incompatible type "str | list[str]"; expected "Iterable[str]"  [arg-type]

psycopg (https://github.com/psycopg/psycopg)
+ psycopg/psycopg/errors.py:80: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/errors.py:556: error: Argument 1 to "Error" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_encodings.py:130: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/rows.py:216: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/rows.py:234: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_struct.py:49: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_py_transformer.py:183: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_py_transformer.py:277: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_py_transformer.py:302: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_py_transformer.py:306: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_py_transformer.py:321: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_py_transformer.py:325: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_py_transformer.py:338: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_py_transformer.py:355: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_conninfo_utils.py:34: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_conninfo_utils.py:42: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_conninfo_attempts_async.py:46: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_conninfo_attempts.py:48: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/conninfo.py:103: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/conninfo.py:140: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_info.py:53: error: Argument 1 to "InternalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/transaction.py:239: error: Argument 1 to "OutOfOrderTransactionNesting" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_typeinfo.py:139: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_capabilities.py:110: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/waiting.py:47: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/waiting.py:160: error: Argument 1 to "InternalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/waiting.py:181: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/waiting.py:221: error: Argument 1 to "InternalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/waiting.py:274: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/waiting.py:285: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/waiting.py:394: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_adapters_map.py:228: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_adapters_map.py:260: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:81: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:92: error: Argument 1 to "ConnectionTimeout" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:101: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:106: error: Argument 1 to "InternalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:117: error: Argument 1 to "CancellationTimeout" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:127: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:130: error: Argument 1 to "InternalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:274: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/generators.py:326: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_tstrings.py:49: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_tstrings.py:74: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_tstrings.py:86: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_tstrings.py:102: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_tstrings.py:115: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_tstrings.py:141: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_queries.py:141: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_queries.py:161: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_queries.py:238: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_queries.py:418: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_queries.py:424: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_queries.py:429: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_queries.py:441: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_queries.py:483: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_pipeline_base.py:168: error: Argument 1 to "PipelineAborted" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_copy_base.py:87: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_copy_base.py:264: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/string.py:52: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:365: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:380: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:396: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:410: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:475: error: Argument 1 to "InternalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:493: error: Argument 1 to "PipelineAborted" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:496: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:500: error: Argument 1 to "InternalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:603: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:606: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:613: error: Argument 1 to "PipelineAborted" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:624: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_cursor_base.py:638: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:260: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:265: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:313: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:486: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:523: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:532: error: Argument 1 to "OperationalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:534: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:574: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:580: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:594: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:600: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:638: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:644: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:653: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:657: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:672: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_connection_base.py:679: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/cursor_async.py:166: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/cursor.py:166: error: Argument 1 to "ProgrammingError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_server_cursor_base.py:167: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/client_cursor.py:62: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_server_cursor_async.py:90: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_server_cursor_async.py:105: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_server_cursor.py:91: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/_server_cursor.py:106: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/connection_async.py:145: error: Argument 1 to "Error" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/connection_async.py:597: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/connection.py:129: error: Argument 1 to "Error" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/connection.py:542: error: Argument 1 to "NotSupportedError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/range.py:441: error: Argument 1 to "InternalError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/range.py:467: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/numeric.py:342: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/json.py:280: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/enum.py:91: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/datetime.py:76: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/datetime.py:246: error: Argument 1 to "InterfaceError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/datetime.py:267: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/datetime.py:269: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/datetime.py:271: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/datetime.py:283: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/datetime.py:285: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]
+ psycopg/psycopg/types/datetime.py:294: error: Argument 1 to "DataError" has incompatible type "str"; expected "Sequence[Any]"  [arg-type]

... (truncated 69 lines) ...

tornado (https://github.com/tornadoweb/tornado)
+ tornado/util.py:179: error: Argument 1 to "frozenset" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ tornado/test/escape_test.py:260: error: List item 0 has incompatible type "tuple[str, str, str]"; expected "tuple[str, Sequence[object], str | None]"  [list-item]
+ tornado/test/escape_test.py:261: error: List item 1 has incompatible type "tuple[str, str, str]"; expected "tuple[str, Sequence[object], str | None]"  [list-item]
+ tornado/test/tcpserver_test.py:158: error: Argument 1 to "sorted" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ tornado/test/tcpserver_test.py:180: error: Argument 1 to "sorted" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ tornado/test/tcpserver_test.py:202: error: Argument 1 to "sorted" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ tornado/test/tcpserver_test.py:229: error: Argument 1 to "sorted" has incompatible type "str"; expected "Iterable[str]"  [arg-type]

prefect (https://github.com/PrefectHQ/prefect)
+ src/prefect/_sdk/naming.py:110: error: Iterating over "str" is disallowed  [misc]
+ src/prefect/_sdk/naming.py:110: note: This is because --disallow-str-iteration is enabled
+ src/prefect/_sdk/naming.py:180: error: Iterating over "str" is disallowed  [misc]
+ src/prefect/_sdk/naming.py:180: note: This is because --disallow-str-iteration is enabled
+ src/prefect/utilities/urls.py:123: error: Iterating over "str | Any" is disallowed  [misc]
+ src/prefect/utilities/urls.py:123: note: This is because --disallow-str-iteration is enabled
+ src/prefect/deployments/runner.py:635: error: List item 1 has incompatible type "tuple[str, Iterable[str] | str | None]"; expected "tuple[str, Iterable[str] | Iterable[int | float | timedelta] | int | float | timedelta | None]"  [list-item]
+ src/prefect/deployments/runner.py:635: error: List item 2 has incompatible type "tuple[str, Iterable[str] | str | None]"; expected "tuple[str, Iterable[str] | Iterable[int | float | timedelta] | int | float | timedelta | None]"  [list-item]
+ src/prefect/cli/cloud/__init__.py:226: error: Argument 1 to "enumerate" has incompatible type "list[str] | list[tuple[T, str]]"; expected "Iterable[Sequence[T | str]]"  [arg-type]
+ src/prefect/infrastructure/provisioners/ecs.py:1345: error: Iterating over "str | Any" is disallowed  [misc]
+ src/prefect/infrastructure/provisioners/ecs.py:1345: note: This is because --disallow-str-iteration is enabled
+ src/prefect/infrastructure/provisioners/container_instance.py:637: error: Iterating over "str | dict[str, Any]" is disallowed  [misc]
+ src/prefect/infrastructure/provisioners/container_instance.py:637: note: This is because --disallow-str-iteration is enabled

mongo-python-driver (https://github.com/mongodb/mongo-python-driver)
+ pymongo/saslprep.py:88: error: Iterating over "str" is disallowed  [misc]
+ pymongo/saslprep.py:88: note: This is because --disallow-str-iteration is enabled
+ bson/decimal128.py:305: error: Iterating over "str" is disallowed  [misc]
+ bson/decimal128.py:305: note: This is because --disallow-str-iteration is enabled
+ pymongo/uri_parser_shared.py:201: error: Iterating over "str" is disallowed  [misc]
+ pymongo/uri_parser_shared.py:201: note: This is because --disallow-str-iteration is enabled
+ pymongo/uri_parser_shared.py:202: error: Iterating over "str" is disallowed  [misc]
+ pymongo/uri_parser_shared.py:202: note: This is because --disallow-str-iteration is enabled
+ pymongo/compression_support.py:64: error: Argument 1 to "list" has incompatible type "str | Iterable[str]"; expected "Iterable[str | Any]"  [arg-type]

pydantic (https://github.com/pydantic/pydantic)
+ pydantic/v1/color.py:59: error: Iterating over "str" is disallowed  [misc]
+ pydantic/v1/color.py:59: note: This is because --disallow-str-iteration is enabled
+ pydantic/v1/schema.py:515: error: Dict entry 0 has incompatible type "str": "str"; expected "str": "Sequence[Collection[str]]"  [dict-item]
+ pydantic/color.py:68: error: Iterating over "str" is disallowed  [misc]
+ pydantic/color.py:68: note: This is because --disallow-str-iteration is enabled
+ pydantic/v1/_hypothesis_plugin.py:124: error: Iterating over "str" is disallowed  [misc]
+ pydantic/v1/_hypothesis_plugin.py:124: note: This is because --disallow-str-iteration is enabled

mkosi (https://github.com/systemd/mkosi)
+ mkosi/versioncomp.py:27:35: error: Argument 1 to "enumerate" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mkosi/versioncomp.py:33:78: error: Argument 2 to "takewhile" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mkosi/versioncomp.py:36:85: error: Argument 2 to "takewhile" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mkosi/config.py:4604:18: error: Iterating over "str | Sequence[Any]" is disallowed  [misc]
+ mkosi/config.py:4604:18: note: This is because --disallow-str-iteration is enabled
+ mkosi/config.py:4638:18: error: Iterating over "str" is disallowed  [misc]
+ mkosi/config.py:4638:18: note: This is because --disallow-str-iteration is enabled
+ mkosi/config.py:4643:31: error: Argument 1 to "__iadd__" of "list" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mkosi/config.py:4652:31: error: Argument 1 to "__iadd__" of "list" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mkosi/config.py:4673:35: error: Argument 1 to "__iadd__" of "list" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mkosi/config.py:4679:27: error: Argument 1 to "__iadd__" of "list" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mkosi/config.py:4682:23: error: Argument 1 to "__iadd__" of "list" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mkosi/config.py:6036:91: error: Iterating over "str" is disallowed  [misc]
+ mkosi/config.py:6036:91: note: This is because --disallow-str-iteration is enabled
+ mkosi/__init__.py:2219:49: error: Iterating over "str" is disallowed  [misc]
+ mkosi/__init__.py:2219:49: note: This is because --disallow-str-iteration is enabled

PyGithub (https://github.com/PyGithub/PyGithub)
+ github/Repository.py:1970: error: Incompatible types in assignment (expression has type "str", target has type "Sequence[Collection[str]]")  [assignment]
+ github/Repository.py:1976: error: Incompatible types in assignment (expression has type "str", target has type "Sequence[Collection[str]]")  [assignment]
+ github/Repository.py:1978: error: Incompatible types in assignment (expression has type "str", target has type "Sequence[Collection[str]]")  [assignment]

bandersnatch (https://github.com/pypa/bandersnatch)
+ src/bandersnatch/configuration.py: note: In member "__init__" of class "BandersnatchConfig":
+ src/bandersnatch/configuration.py:77: error: Argument "delimiters" to "__init__" of "RawConfigParser" has incompatible type "str"; expected "Sequence[str]"  [arg-type]

pylox (https://github.com/sco1/pylox)
+ pylox/builtins/py_builtins.py:358: error: Argument 1 to "_lox_arrayize" has incompatible type "str"; expected "Iterable[Any]"  [arg-type]
+ tests/builtins/test_loxarrayize.py:9: error: Argument 1 to "deque" has incompatible type "str"; expected "Iterable[str]"  [arg-type]

cibuildwheel (https://github.com/pypa/cibuildwheel)
+ cibuildwheel/options.py:258: error: Unpacked dict entry 0 has incompatible type "Mapping[str, str | Sequence[str]]"; expected "SupportsKeysAndGetItem[str, int | Sequence[str | int | bool]]"  [dict-item]
+ cibuildwheel/options.py:258: error: Unpacked dict entry 1 has incompatible type "Mapping[str, str | Sequence[str]]"; expected "SupportsKeysAndGetItem[str, int | Sequence[str | int | bool]]"  [dict-item]

aiohttp (https://github.com/aio-libs/aiohttp)
+ aiohttp/hdrs.py:114:41: error: Argument 1 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/hdrs.py:114:60: error: Argument 2 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/hdrs.py:117:41: error: Argument 1 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/hdrs.py:117:63: error: Argument 2 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/hdrs.py:120:41: error: Argument 1 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/hdrs.py:120:55: error: Argument 2 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/helpers.py:420:28: error: Argument 1 to "set" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/helpers.py:448:41: error: Argument 1 to "set" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/helpers.py:455:44: error: Argument 1 to "set" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/http_parser.py:59:33: error: Argument 1 to "set" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/multipart.py:77:46: error: Argument 1 to "set" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ aiohttp/web_urldispatcher.py:573:39: error: Dict entry 0 has incompatible type "str": "str"; expected "str": "SupportsInt | Sequence[str | SupportsInt | float]"  [dict-item]
+ aiohttp/web_urldispatcher.py:573:39: note: See https://mypy.rtfd.io/en/stable/_refs.html#code-dict-item for more info

colour (https://github.com/colour-science/colour)
+ colour/utilities/verbose.py:234: error: Argument 1 to "chain" has incompatible type "*list[str | list[str]]"; expected "Iterable[str]"  [arg-type]
+ colour/geometry/primitives.py:375: error: Iterating over "Literal['-x', '+x', '-y', '+y', '-z', '+z', 'xy', 'xz', 'yz', 'yx', 'zx', 'zy']" is disallowed  [misc]
+ colour/geometry/primitives.py:375: note: This is because --disallow-str-iteration is enabled
+ colour/io/ctl.py:428: error: Argument 2 to "optional" has incompatible type "str"; expected "Sequence[str]"  [arg-type]
+ colour/io/ctl.py:553: error: Argument 2 to "optional" has incompatible type "str"; expected "Sequence[str]"  [arg-type]
+ colour/plotting/common.py:881: error: Iterating over "str" is disallowed  [misc]
+ colour/plotting/common.py:881: note: This is because --disallow-str-iteration is enabled
+ colour/plotting/common.py:886: error: Argument 2 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ colour/plotting/volume.py:257: error: Argument 1 to "enumerate" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ colour/plotting/volume.py:285: error: Argument 1 to "enumerate" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ colour/plotting/volume.py:626: error: Argument 1 to "enumerate" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ colour/plotting/volume.py:634: error: Argument 1 to "enumerate" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ colour/plotting/temperature.py:617: error: Argument 1 to "optional" has incompatible type "str | Sequence[str] | None"; expected "Sequence[str] | None"  [arg-type]
+ colour/utilities/tests/test_array.py:536: error: Argument 1 to "zip" has incompatible type "str"; expected "Iterable[str]"  [arg-type]

python-chess (https://github.com/niklasf/python-chess)
+ chess/__init__.py:1186: error: Iterating over "str" is disallowed  [misc]
+ chess/__init__.py:1186: note: This is because --disallow-str-iteration is enabled
+ chess/__init__.py:1213: error: Iterating over "str" is disallowed  [misc]
+ chess/__init__.py:1213: note: This is because --disallow-str-iteration is enabled
+ chess/__init__.py:2746: error: Iterating over "str" is disallowed  [misc]
+ chess/__init__.py:2746: note: This is because --disallow-str-iteration is enabled
+ chess/__init__.py:2928: error: Argument 1 to "chain" has incompatible type "str"; expected "Iterable[str | None]"  [arg-type]
+ chess/variant.py:841: error: Incompatible default for argument "symbols" (default has type "str", argument has type "Iterable[str]")  [assignment]
+ chess/variant.py:1036: error: Iterating over "str" is disallowed  [misc]
+ chess/variant.py:1036: note: This is because --disallow-str-iteration is enabled
+ chess/variant.py:1037: error: Iterating over "str" is disallowed  [misc]
+ chess/variant.py:1037: note: This is because --disallow-str-iteration is enabled
+ chess/syzygy.py:388: error: Argument 1 to "sorted" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ chess/syzygy.py:389: error: Argument 1 to "sorted" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ chess/syzygy.py:390: error: Iterating over "str" is disallowed  [misc]
+ chess/syzygy.py:390: note: This is because --disallow-str-iteration is enabled
+ chess/engine.py:2498: error: Iterating over "str" is disallowed  [misc]
+ chess/engine.py:2498: note: This is because --disallow-str-iteration is enabled

mypy_primer (https://github.com/hauntsaninja/mypy_primer)
+ mypy_primer/utils.py:92: error: Argument 1 to "join" has incompatible type "str | list[str]"; expected "Iterable[str]"  [arg-type]

zipp (https://github.com/jaraco/zipp)
+ zipp/glob.py:25: error: Argument 1 to "set" has incompatible type "str"; expected "Iterable[str]"  [arg-type]

meson (https://github.com/mesonbuild/meson)
+ mesonbuild/depfile.py:19:18: error: Iterating over "str" is disallowed  [misc]
+ mesonbuild/depfile.py:19:18: note: This is because --disallow-str-iteration is enabled
+ mesonbuild/utils/universal.py:946:16: error: Iterating over "str | Iterable[str]" is disallowed  [misc]
+ mesonbuild/utils/universal.py:946:16: note: This is because --disallow-str-iteration is enabled
+ mesonbuild/utils/universal.py:1161:17: error: Iterating over "str" is disallowed  [misc]
+ mesonbuild/utils/universal.py:1161:17: note: This is because --disallow-str-iteration is enabled
+ mesonbuild/utils/universal.py:1182:18: error: Iterating over "str" is disallowed  [misc]
+ mesonbuild/utils/universal.py:1182:18: note: This is because --disallow-str-iteration is enabled
+ mesonbuild/utils/universal.py:1204:18: error: Iterating over "str" is disallowed  [misc]
+ mesonbuild/utils/universal.py:1204:18: note: This is because --disallow-str-iteration is enabled
+ mesonbuild/utils/universal.py:1904:27: error: Argument 1 to "__iadd__" of "list" has incompatible type "str | list[str]"; expected "Iterable[str | Program]"  [arg-type]
+ mesonbuild/utils/universal.py:1913:27: error: Argument 1 to "__iadd__" of "list" has incompatible type "str | list[str]"; expected "Iterable[str | Program]"  [arg-type]
+ mesonbuild/cargo/cfg.py:60:27: error: Argument 1 to "enumerate" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mesonbuild/cmdline.py:121:26: error: Argument 1 to "__init__" of "Action" has incompatible type "str"; expected "Sequence[str]"  [arg-type]
+ mesonbuild/cmdline.py:141:26: error: Argument 1 to "__init__" of "Action" has incompatible type "str"; expected "Sequence[str]"  [arg-type]
+ mesonbuild/interpreterbase/helpers.py:22:16: error: Incompatible return value type (got "list[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]", expected "list[TYPE_var]")  [return-value]
+ mesonbuild/interpreterbase/helpers.py:22:16: note: "list" is invariant -- see https://mypy.readthedocs.io/en/stable/common_issues.html#variance
+ mesonbuild/interpreterbase/helpers.py:22:16: note: Consider using "Sequence" instead, which is covariant
+ mesonbuild/interpreterbase/helpers.py:23:34: error: Incompatible types in assignment (expression has type "list[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]", variable has type "list[TYPE_var]")  [assignment]
+ mesonbuild/interpreterbase/helpers.py:23:34: note: "list" is invariant -- see https://mypy.readthedocs.io/en/stable/common_issues.html#variance
+ mesonbuild/interpreterbase/helpers.py:23:34: note: Consider using "Sequence" instead, which is covariant
+ mesonbuild/interpreterbase/helpers.py:39:20: error: Incompatible return value type (got "dict[str, int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]", expected "TYPE_elementary | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]")  [return-value]
+ mesonbuild/interpreterbase/helpers.py:43:12: error: Incompatible return value type (got "tuple[list[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]], dict[str, int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]]", expected "tuple[list[TYPE_var], dict[str, TYPE_var]]")  [return-value]
+ mesonbuild/cmake/common.py:85:14: error: Iterating over "str" is disallowed  [misc]
+ mesonbuild/cmake/common.py:85:14: note: This is because --disallow-str-iteration is enabled
+ mesonbuild/cmake/common.py:177:56: error: Argument 1 to "join" of "str" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mesonbuild/compilers/cuda.py:219:24: error: Argument 1 to "set" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mesonbuild/compilers/cuda.py:225:24: error: Argument 1 to "set" has incompatible type "str"; expected "Iterable[str]"  [arg-type]
+ mesonbuild/interpreterbase/decorators.py:114:10: error: Argument 1 to "__call__" of "_Wrapper" has incompatible type "def wrapper(self: InterpreterObject, other: TYPE_var) -> TYPE_var"; expected "def (self: InterpreterObject, other: TYPE_var) -> int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]"  [arg-type]
+ mesonbuild/interpreterbase/decorators.py:114:16: error: Argument 1 to "wraps" has incompatible type "_TV_FN_Operator"; expected "Callable[[Any, Any], int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"  [arg-type]
+ mesonbuild/interpreterbase/decorators.py:207:68: error: Argument 1 to "zip_longest" has incompatible type "list[TYPE_elementary | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"; expected "Iterable[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var] | type[Any] | tuple[type[Any], ...]]"  [arg-type]
+ mesonbuild/interpreterbase/decorators.py:226:28: error: Argument 1 to "list" has incompatible type "list[TYPE_elementary | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"; expected "Iterable[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"  [arg-type]
+ mesonbuild/interpreterbase/decorators.py:228:34: error: Argument 1 to "tuple" has incompatible type "list[TYPE_elementary | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"; expected "Iterable[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"  [arg-type]
+ mesonbuild/interpreterbase/decorators.py:232:43: error: Argument 1 to "list" has incompatible type "list[TYPE_elementary | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"; expected "Iterable[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"  [arg-type]
+ mesonbuild/interpreterbase/decorators.py:234:38: error: Argument 1 to "tuple" has incompatible type "list[TYPE_elementary | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"; expected "Iterable[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"  [arg-type]
+ mesonbuild/interpreterbase/decorators.py:236:34: error: Argument 1 to "tuple" has incompatible type "list[TYPE_elementary | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"; expected "Iterable[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"  [arg-type]
+ mesonbuild/interpreterbase/interpreterbase.py:287:32: error: Argument 1 to "_holderify" of "InterpreterBase" has incompatible type "dict[str, int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]"; expected "TYPE_var | InterpreterObject"  [arg-type]
+ mesonbuild/interpreterbase/interpreterbase.py:568:16: error: Incompatible return value type (got "tuple[list[int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]], dict[str, int | dict[str, TYPE_elementary] | HoldableObject | MesonInterpreterObject | Sequence[TYPE_var] | dict[str, TYPE_var]]]", expected "tuple[list[TYPE_var], dict[str, TYPE_var]]")  [return-value]
+ mesonbuild/cmake/interpreter.py:287:40: error: Iterating over "str" is disallowed  [misc]
+ mesonbuild/cmake/interpreter.py:287:40: note: This is because --disallow-str-iteration is enabled
+ mesonbuild/cmake/interpreter.py:1045:22: error: Incompatible types in assignment (expression has type "dict[str, int | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]]", variable has type "dict[str, str | int | bool | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]] | None")  [assignment]
+ mesonbuild/cmake/interpreter.py:1057:22: error: Incompatible types in assignment (expression has type "dict[str, int | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]]", variable has type "dict[str, str | int | bool | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]] | None")  [assignment]
+ mesonbuild/cmake/interpreter.py:1071:85: error: Argument 3 to "function" has incompatible type "dict[str, int | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]]"; expected "dict[str, str | int | bool | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]] | None"  [arg-type]
+ mesonbuild/cmake/interpreter.py:1071:85: note: "dict" is invariant -- see https://mypy.readthedocs.io/en/stable/common_issues.html#variance
+ mesonbuild/cmake/interpreter.py:1071:85: note: Consider using "Mapping" instead, which is covariant in the value type
+ mesonbuild/cmake/interpreter.py:1071:86: error: Dict entry 0 has incompatible type "str": "str"; expected "str": "int | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]"  [dict-item]
+ mesonbuild/cmake/interpreter.py:1175:45: error: Incompatible types in assignment (expression has type "dict[str, int | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]]", variable has type "dict[str, str | int | bool | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]]")  [assignment]
+ mesonbuild/cmake/interpreter.py:1175:45: note: "dict" is invariant -- see https://mypy.readthedocs.io/en/stable/common_issues.html#variance
+ mesonbuild/cmake/interpreter.py:1175:45: note: Consider using "Mapping" instead, which is covariant in the value type
+ mesonbuild/cmake/interpreter.py:1207:45: error: Incompatible types in assignment (expression has type "dict[str, int | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]]", variable has type "dict[str, str | int | bool | Path | BaseNode | Sequence[str | int | bool | Path | BaseNode]]")  [assignment]
+ mesonbuild/cmake/interpreter.py:1207:45: note: "dict" is invariant -- see https://mypy.readthedocs.io/en/stable/common_issues.html#variance
+ mesonbuild/cmake/interpreter.py:1207:45: note: Consider using "Mapping" instead, which is covariant in the value type

... (truncated 2371 lines) ...```

michaelm-openai and others added 2 commits January 13, 2026 11:13

Add --disallow-str-iteration flag

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JelleZijlstra reviewed Jan 13, 2026

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address feedback

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michaelm-openai and others added 2 commits January 13, 2026 15:27

actually commit the patch + more adjustments

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JelleZijlstra reviewed Jan 13, 2026

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address more feedback + undo reversible

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michaelm-openai requested a review from JelleZijlstra January 14, 2026 06:05

[pre-commit.ci] auto fixes from pre-commit.com hooks

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Swap iter overloads to preserve previous error behavior

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experiment enabling by default

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Add --disallow-str-iteration flag #20577

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