Hmm; I wrote a long description so can add more, but I'm having a curious problem with some tests and namespaced packages (pants 2.50, python 3.9). Bah, some description necessary anyway 🙂 I have three "namespaced modules", call them

a

(dir structure

a/ns/a...

where this

ns

contains

__init_.py

)_ as well as b and c (which look like

b/ns/b..

and

c/ns/c...

). root directories a,b,c have SOURCE_ROOT set and a BUILD for

python_requirements

, and all three

ns/X

directories have a BUILD for

python_library

. I will say that

b/ns

and

c/ns

don't have a BUILD because there are no source files there (including an

__init__py

because I didn't want it to conflict with

a

). Okay. AAaaaanyway, I have a few

python_test

targets that use

b

or

c

, and they seem to run OK (the

./pants dependencies

shows

b/ns/b/__init__.py

and relevant files, and the tests run). But I have one irritating test that isn't playing nice:

./pants dependencies

shows

b/ns/b/_init_.py

and all files that I think I'm importing, but running the test fails with the equivalent of

module/tests/test_file.py:2: in <module>
  from ns.b.submodule.submodule import Thing
E: ModuleNotFoundError: No module named `ns.b`

So I don't quite understand what's gone wrong. I've stared at comparable BUILD files to try and understand what's different. Is there a way to force rebuilding of the test pex just to make sure there's not a caching issue? Or something else I should look at?

So, why do you have

__init__.py

files / do they have namespace package declarations in them and nothing else?

Of course, and thanks. Atually this may indeed be the issue; I had thought that one package in the namespace could have an

__init__.py

but no others could or it would be overwritten, but what may well be the case is that no packages in the namespace can have an

__init__.py

in the main namespace. Let me try that, because that indeed is where the collision seems to be happening (looking at the failed test, it's bringing in something in the main package, where the passing test isn't).

Yeah, namespace packages don't work like you'd think in Python. You either need all of them to have the exact same

__init__.py

containing one of these: + https://packaging.python.org/guides/packaging-namespace-packages/#pkgutil-style-namespace-packages + https://packaging.python.org/guides/packaging-namespace-packages/#pkg-resources-style-namespace-packages Or else use implicit namespace packages (aka delete your

__init__.py

files.