Module "jaraco" has no attribute "env" (from jaraco import env)

[jaraco]

Bug Report

In jaraco/pip-run#79, I noticed that the mypy tests started failing and traced the emergent failure to enhancements in the typing of a sibling submodule.

To Reproduce

import jaraco.functools
from jaraco import env

 draft @ pip-run mypy 'jaraco.functools==3.9' jaraco.env -- -m mypy --ignore-missing-imports test.py
test.py:2: error: Module "jaraco" has no attribute "env"  [attr-defined]
Found 1 error in 1 file (checked 1 source file)

Run instead with jaraco.functools<3.9 and mypy succeeds:

 draft @ pip-run mypy 'jaraco.functools<3.9' jaraco.env -- -m mypy --ignore-missing-imports test.py
Success: no issues found in 1 source file

jaraco.functools 3.9 moved functools to its own submodule and declared that module as typed (jaraco/jaraco.functools#22).

Expected Behavior

Changes to a sibling submodule shouldn't affect the reliable checking when importing a module. mypy should detect from module import submodule as valid.

Your Environment

• Mypy version used: 1.5.1
• Mypy command-line flags: --ignore-missing-imports
• Mypy configuration options from mypy.ini (and other config files): none in repro, but some in project.
• Python version used: 3.11.4

[jaraco]

Removing the py.typed from jaraco.functools bypasses the issue:

 draft @ py -3.11 -m venv .venv
 draft @ py -m pip install mypy jaraco.functools jaraco.env
...
Successfully installed jaraco.env-1.0.0 jaraco.functools-3.9.0 more-itertools-10.1.0 mypy-1.5.1 mypy-extensions-1.0.0 typing-extensions-4.7.1

 draft @ ls .venv/lib/python3.11/site-packages/jaraco/functools
__init__.py  __init__.pyi __pycache__  py.typed
 draft @ rm .venv/lib/python3.11/site-packages/jaraco/functools/py.typed
 draft @ py -m mypy --ignore-missing-imports test.py
Success: no issues found in 1 source file

[jaraco]

Note that jaraco is a PEP 420 namespace package.

[jaraco]

Here's something interesting. If I install jaraco.functools and jaraco.env into ., the issue doesn't occur:

 draft @ rm -r .venv
 draft @ ls
test.py
 draft @ pip install --quiet --target . jaraco.functools==3.9 jaraco.env
 draft @ mypy --ignore-missing-imports test.py
Success: no issues found in 1 source file

It only occurs if jaraco.functools and jaraco.env are installed to site-packages. That's weird, right?

[jaraco]

I am able to replicate the issue more simply, without the official versions of jaraco.functools or jaraco.env with empty modules thus:

 draft @ py -3.11 -m venv .venv
 draft @ mkdir -p .venv/lib/python3.11/site-packages/jaraco/functools
 draft @ touch .venv/lib/python3.11/site-packages/jaraco/env.py
 draft @ touch .venv/lib/python3.11/site-packages/jaraco/functools/__init__.py
 draft @ touch .venv/lib/python3.11/site-packages/jaraco/functools/py.typed
 draft @ py -m pip install -q mypy

[notice] A new release of pip is available: 23.0.1 -> 23.2.1
[notice] To update, run: /Users/jaraco/draft/.venv/bin/python -m pip install --upgrade pip
 draft @ py -m mypy test.py
test.py:2: error: Module "jaraco" has no attribute "env"  [attr-defined]
Found 1 error in 1 file (checked 1 source file)

[tmke8]

My guess: both jaraco.env and jaraco.functools were previously untyped, so mypy just raised a missing-import for it (which you're ignoring) and moved on. But now, jaraco.functools is typed, and I guess mypy now also treats jaraco as typed? And so it looks for jaraco.env but that is still not typed, so mypy can't find it. So, the import error turned into an attribute error.

[asottile-sentry]

likely duplicate of #10360