if I run

pants lint check ::

it appears wait for flake8 to finish before starting mypy. Why is that? Did I somehow add a dependency from mypy to flake8?

The flake8 run is in the lint goal and mypy in the check goal and goals are still serial: https://github.com/pantsbuild/pants/issues/10542

🤔

IOW

pants check lint ::

will lead to the same observation, but in reverse. Steps (rules) registered in the same goal all run maximally in parallel given cpu core constraints / data-flow constraints. Goals, though, proceed serially from one to the next.