I have a few third-party libraries I'm using in my project that don't have type stubs. I'd like to write my own stubs for these such that

pants check

is able to pick them up. Is there a recommended way of setting this up?

Pants check just delegates to mypy or pyright (https://www.pantsbuild.org/stable/docs/python/goals/check) Are you running into any particular problems?

Yes -- I'm using

absl

but it does not include type stubs. I've generated my own and put them in the repo, but

pants check

does not find them. I've tried adding them as resource dependencies, but they're not getting found. Running Pyright in the exported virtual environment is able to pick them up.

Have you passed in any additional configuration (https://microsoft.github.io/pyright/#/configuration)? That's strange though, if pyright runs correctly on the exported env, it should also "just work" as part of check.... I wonder if there is a source-root issue? So, maybe pyright thinks you're running in a different directory

That's right a virtual env generated with

pants export

Okay, so if you run

pants --keep-sandboxes=always check --only=pyright ::

and then check out the created sandbox, does pyright work in there?

I'm not sure how namespace packages interact with pyright. Another library I've created stubs for is

boto3

and that one seems to work. I suspect it's working for some libraries and not others due to issues with packages vs namespace packages, but I don't know enough about how Pyright resolves paths to say. I know I've had issues in the past with it finding generated protos when there's an init.py in the corresponding source directory.

Yeah, my guess was something to do with that as well. Or, maybe it's just the path. Once you create sandbox, you can try using the __run.sh directly - but if your typings aren't in the sandbox, that'll be a quick check Then you can experiment with pyright configuration in the sandbox directly, and back-apply it into Pants

Stepping back, it turns out

absl

does actually have type stubs and I just have an old version pinned...