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minor annoyance, but it looks like pants thinks it...
# general
h
minor annoyance, but it looks like pants thinks it can't infer a dependency when it should actually be able to? I'm not sure how to best summarize the problem, so more details in thread 🧵
MWE (with 
[pants-infer].unowned_dependency_behavior = "error"
)
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# tests/test.py
from importlib import resources
from tests.html_examples import __package__ as html_package

def test_example():
    assert resources.files(html_package).joinpath("example.html").exists()
    assert resources.files(html_package).joinpath("example.html").read_text()
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# tests/BUILD
python_tests(
    overrides={
        "test.py": {
            "dependencies": ["tests/html_examples:html-resources"],
        },
    },
)
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# tests/html_examples/BUILD
resources(
    name="html-resources",
    sources=["*.html"],
)
running 
pants test ::
will raise a 
UnownedDependencyError
with Pants complaining that it cannot infer the owners for 
tests.html_examples.__package__
. however, adding a 
# pants: no-infer-dep
comment allows the test to pass, indicating to me that it's able to find the dependency just fine. alternatively, if I add a 
tests/html_examples/__init__.py
file and a 
python_sources()
to 
tests/html_examples/BUILD
, pants is also able to pass just fine, even though the init file should be unnecessary when using 
importlib.resources
b
Hm, I would guess Pants is assuming that Python's "normal" rules for modules apply, i.e. 
__init__.py
is required, and doesn't realise that this particular incantation is valid too. Could you file an issue? The MWE is great, it'd be good to have the required 
pants.toml
included too 👍
h
it sometimes feels like python's rules are always in flux, but as of Python 3.3, namespace packages are allowed, i.e. packages with no 
__init__.py
file. 
importlib.resources
supports namespace packages, though 
pkgutil
doesn't my 
pants.toml
is fairly bare, with the only thing i believe to be relevant here is the dependency behavior mentioned above:
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# pants.toml
...
[python-infer]
unowned_dependency_behavior = "error"
use_rust_parser = true
...
for reference, this is the error message:
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pants test ::    
14:13:54.50 [ERROR] 1 Exception encountered:

Engine traceback:
  in `test` goal

UnownedDependencyError: Pants cannot infer owners for the following imports in the target tests/test.py:

  * tests.html_examples.__package__ (line: 9)

If you do not expect an import to be inferrable, add `# pants: no-infer-dep` to the import line. Otherwise, see <https://www.pantsbuild.org/2.20/docs/using-pants/troubleshooting-common-issues#import-errors-and-missing-dependencies> for common problems.
b
Ah, I see. Can you file an issue? Thanks
c
I think it might be that we don't handle 
___package___
, so Pants can't make the dep link or find the owner. But the explicit dependency in the BUILD file will cause html-resources to show up. So even if Pants doesn't have an owner for that import, Python will still be able to import from that file/package
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