ty 0.0.33 emits unknown-argument errors on pydantic Field(alias=...) constructions even with populate_by_name=True

When upgrading or re-installing ty (Astral's type checker), versions from 2026-04-28 onward (0.0.33+) flag valid pydantic model constructions where the python attribute name differs from the alias as error[unknown-argument]: Argument 'X' does not match any known parameter. This happens even when the model has model_config = ConfigDict(populate_by_name=True) and the field is declared X: T = Field(default=..., alias="Y"). Earlier ty versions (0.0.32 and prior) did not emit this diagnostic, so projects can suddenly find their pre-commit/CI failing with no code change after a ty release. The constructions are runtime-correct; pydantic accepts both the python attribute name and the alias. This is reproducible: after uv sync and uvx ty check, a model with aliased fields will be flagged at every call site that uses the python attribute name. Verified 2026-04-28 against ty 0.0.33 / pydantic 2.12.5.

If ty check newly reports unknown-argument errors against Field(alias=...) call sites after a ty upgrade, suppress with inline # ty: ignore[unknown-argument] rather than restructuring valid pydantic constructions. Pin the ty version in pre-commit configuration if you want stable diagnostics across runs (the default entry: uvx ty check ... always pulls latest). Verify by running uvx ty check <pkg> --python .venv before and after a ty upgrade and diffing the diagnostic count.