I'm running into an error retrieving stubs when running

pants check ::

. I've reproduced the error in a minimal setup. Basically, I have one file which imports a third-party dep and a mypy_stub to include types for that 3rd party dep.

# ./modules/validator.py
from email_validator import EmailNotValidError, validate_email

# ./mypy_stubs/email_validator/__init__.pyi
... contains some typing info ...

pipenv run mypy

runs successfully on these files. However,

./pants check ::

will give me this error:

modules/validator.py:1: error: Skipping analyzing "email_validator": module is installed, but missing library stubs or py.typed marker

My setup also exists here in this repo: https://github.com/chrisplim/pants-check-error-mypy-stub

I haven't tried running it yet, but the first thing to be aware of is that pants runs things in a sandbox, so that there's less chance of "works on my machine": if it works on one computer, it'll work on others in the same way. This does mean that pants needs to know about all of the dependencies and files for any given command. For your particular reproducer (which is very handy, thanks!), this would suggest that pants needs to know about the type stubs, by loading them into pants with a

BUILD

file and

python_sources()

target.

Yep - check out https://www.pantsbuild.org/docs/python-check-goal#first-party-type-stubs-pyi-files for details

@broad-processor-92400 Thanks Huon, that was exactly it!