This causes mypy build errors to be reported when I run stubtest --mypy-config-file=pyproject.toml numpy (in numpy/numtype), where the pyproject.toml contains:

[tool.mypy]
# [...]
strict_bytes = true

The build error is of the overload-cannot-match kind, and is caused by a memoryview promotion in https://github.com/numpy/numtype/blob/2a9953a1be3c14660f29aabbaffc3e7fb6c2135a/src/numpy-stubs/__init__.pyi#L1143.

The workaround is to use the superseded (and undocumented) flags instead:

[tool.mypy]
# [...]
disable_bytearray_promotion = true
disable_memoryview_promotion = true

Running the command again with this pyproject.toml shows no build errors.