Diff from mypy_primer, showing the effect of this PR on type check results on a corpus of open source code:

static-frame (https://github.com/static-frame/static-frame)
+ static_frame/core/index_hierarchy.py:179: error: No overload variant of "tile" matches argument types "ndarray[tuple[int], dtype[signedinteger[_64Bit]]]", "signedinteger[_32Bit | _64Bit]"  [call-overload]
+ static_frame/core/index_hierarchy.py:179: note: Possible overload variants:
+ static_frame/core/index_hierarchy.py:179: note:     def [_ScalarT: generic[Any]] tile(A: _SupportsArray[dtype[_ScalarT]] | _NestedSequence[_SupportsArray[dtype[_ScalarT]]], reps: int | Sequence[int]) -> ndarray[tuple[Any, ...], dtype[_ScalarT]]
+ static_frame/core/index_hierarchy.py:179: note:     def tile(A: Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], reps: int | Sequence[int]) -> ndarray[tuple[Any, ...], dtype[Any]]

optuna (https://github.com/optuna/optuna)
+ optuna/importance/_fanova/_tree.py:177: error: Incompatible types in assignment (expression has type "floating[Any]", variable has type "float")  [assignment]

pandas (https://github.com/pandas-dev/pandas)
+ pandas/core/_numba/kernels/var_.py:113: error: Incompatible types in assignment (expression has type "float", variable has type "ndarray[tuple[Any, ...], dtype[Any]]")  [assignment]
+ pandas/core/_numba/kernels/var_.py:120: error: Argument 7 to "add_var" has incompatible type "ndarray[tuple[Any, ...], dtype[Any]]"; expected "float"  [arg-type]
+ pandas/core/_numba/kernels/var_.py:138: error: Incompatible types in assignment (expression has type "float", variable has type "ndarray[tuple[Any, ...], dtype[Any]]")  [assignment]
+ pandas/core/_numba/kernels/var_.py:145: error: Argument 7 to "add_var" has incompatible type "ndarray[tuple[Any, ...], dtype[Any]]"; expected "float"  [arg-type]
+ pandas/core/_numba/kernels/var_.py:215: error: Incompatible types in assignment (expression has type "int", variable has type "ndarray[tuple[Any, ...], dtype[signedinteger[_64Bit]]]")  [assignment]
+ pandas/core/_numba/kernels/var_.py:215: error: Incompatible types in assignment (expression has type "float", variable has type "ndarray[tuple[Any, ...], Any]")  [assignment]
+ pandas/core/_numba/kernels/var_.py:217: error: Argument 2 to "add_var" has incompatible type "ndarray[tuple[Any, ...], dtype[signedinteger[_64Bit]]]"; expected "int"  [arg-type]
+ pandas/core/_numba/kernels/var_.py:218: error: Argument 3 to "add_var" has incompatible type "ndarray[tuple[Any, ...], Any]"; expected "float"  [arg-type]
+ pandas/core/_numba/kernels/var_.py:219: error: Argument 4 to "add_var" has incompatible type "ndarray[tuple[Any, ...], Any]"; expected "float"  [arg-type]
+ pandas/core/_numba/kernels/var_.py:220: error: Argument 5 to "add_var" has incompatible type "ndarray[tuple[Any, ...], Any]"; expected "float"  [arg-type]
+ pandas/core/_numba/kernels/var_.py:221: error: Argument 6 to "add_var" has incompatible type "ndarray[tuple[Any, ...], dtype[signedinteger[_64Bit]]]"; expected "int"  [arg-type]
+ pandas/core/_numba/kernels/var_.py:222: error: Argument 7 to "add_var" has incompatible type "ndarray[tuple[Any, ...], Any]"; expected "float"  [arg-type]
+ pandas/core/_numba/kernels/sum_.py:207: error: Incompatible types in assignment (expression has type "int", variable has type "ndarray[tuple[Any, ...], dtype[signedinteger[_64Bit]]]")  [assignment]
+ pandas/core/_numba/kernels/sum_.py:209: error: Argument 2 to "add_sum" has incompatible type "ndarray[tuple[Any, ...], dtype[signedinteger[_64Bit]]]"; expected "int"  [arg-type]
+ pandas/core/_numba/kernels/sum_.py:212: error: Argument 5 to "add_sum" has incompatible type "ndarray[tuple[Any, ...], dtype[signedinteger[_64Bit]]]"; expected "int"  [arg-type]
+ pandas/core/_numba/kernels/mean_.py:104: error: Incompatible types in assignment (expression has type "float", variable has type "ndarray[tuple[Any, ...], dtype[Any]]")  [assignment]
+ pandas/core/_numba/kernels/mean_.py:111: error: Argument 7 to "add_mean" has incompatible type "ndarray[tuple[Any, ...], dtype[Any]]"; expected "float"  [arg-type]
+ pandas/core/_numba/kernels/mean_.py:129: error: Incompatible types in assignment (expression has type "float", variable has type "ndarray[tuple[Any, ...], dtype[Any]]")  [assignment]
+ pandas/core/_numba/kernels/mean_.py:136: error: Argument 7 to "add_mean" has incompatible type "ndarray[tuple[Any, ...], dtype[Any]]"; expected "float"  [arg-type]
+ pandas/core/_numba/kernels/mean_.py:142: error: Incompatible types in assignment (expression has type "ndarray[tuple[Any, ...], dtype[Any]]", variable has type "float")  [assignment]
+ pandas/core/indexes/multi.py:4334: error: No overload variant of "tile" matches argument types "ndarray[tuple[int], dtype[Any]]", "signedinteger[_32Bit | _64Bit]"  [call-overload]
+ pandas/core/indexes/multi.py:4334: note: Possible overload variants:
+ pandas/core/indexes/multi.py:4334: note:     def [_ScalarT: generic[Any]] tile(A: _SupportsArray[dtype[_ScalarT]] | _NestedSequence[_SupportsArray[dtype[_ScalarT]]], reps: int | Sequence[int]) -> ndarray[tuple[Any, ...], dtype[_ScalarT]]
+ pandas/core/indexes/multi.py:4334: note:     def tile(A: _Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], reps: int | Sequence[int]) -> ndarray[tuple[Any, ...], dtype[Any]]

colour (https://github.com/colour-science/colour)
+ colour/io/ocio.py:163: error: Incompatible return value type (got "floating[_16Bit] | floating[_32Bit] | float64", expected "ndarray[tuple[Any, ...], dtype[floating[_16Bit] | floating[_32Bit] | float64]]")  [return-value]
+ colour/io/ctl.py:313: error: Incompatible return value type (got "floating[_16Bit] | floating[_32Bit] | float64", expected "ndarray[tuple[Any, ...], dtype[floating[_16Bit] | floating[_32Bit] | float64]]")  [return-value]

🤔 can this really be due to using Incomplete instead of Any?

🤔 can this really be due to using Incomplete instead of Any?

I have no idea what's going on there, to be honest. Maybe it's related to a mypy bug?

Thanks!