How to reproduce

Set up the project the mypy_primer way:

git clone https://github.com/mit-ll-responsible-ai/hydra-zen
cd hydra-zen
uv venv
uv pip install pydantic beartype hydra-core
source .venv/bin/activate

Then run the following command repeatedly:

ty check src tests/annotations

Leads to either 541, 543, or 544 diagnostics.

When TY_MAX_PARALLELISM is set to 1, ty consistently reports 544 diagnostics.