I have a monorepo with multiple top-level projects and a couple of shared projects. Here’s a fragment of the roots

common/src/python
common/test/python
directory_pull/src/docker
directory_pull/src/python
directory_pull/test/python
mypy-stubs/src/python
project_management/src/docker
project_management/src/python
project_management/test/python

Each project has the same code structure within the

src/python

directory. So, there is a

run.py

in each of

directory_pull/src/python

and

project_management/src/python

Everything works fine within each project, but when I run

pants check ::

mypy complains about duplicate modules across the projects. If I add a directory above

run.py

like

directory_pull/src/python/directory_pull

then there is no error. I’m curious what is going on with my original organization that yields this behavior, and whether there is an alternative solution to the slight reorganization

Its exactly like it says. MyPy sees 2x run.py, so a duplicate module. If there is a way to exclude run.py from MyPy checks, that's one path forward, but only if you can swallow doing that. Otherwise, IIUC, a single Pants command line invocation can't get you what you want here. You need to run it a few times.

Thanks @enough-analyst-54434. I was misunderstanding the role of the source roots in this case. And, no, I haven’t had a configuration where I didn’t get this error after adding more projects