.pyi file not detected for single .py file in site-packages

[brettcannon]

Bug Report

A .pyi file next to a top-level .py file in site-packages is not being picked up.

P.S.: Docs are also inconsistent on naming of stubs-only packages. https://mypy.readthedocs.io/en/stable/installed_packages.html#installed-packages says types-<name> and then later says <name>-stubs.

To Reproduce

• Install microvenv
• Write a microvenv.pyi file in site-packages next to microvenv.py
• Run mypy with code importing microvenv

Example microvenv.pyi:

import os

def create(env_dir: os.PathLike[str] | str = ...) -> None: ...

Expected Behavior

No error about missing type stubs or py.typed.

Actual Behavior

nox > mypy src/py_pip.py
src/py_pip.py:11: error: Skipping analyzing "microvenv": module is installed, but missing library stubs or py.typed marker  [import]
src/py_pip.py:11: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports

I verified the .pyi file worked by copying to the same directory as the code being analyzed.

Your Environment

• Mypy version used: 1.4.1
• Mypy command-line flags: None
• Mypy configuration options from mypy.ini (and other config files): None
• Python version used: Python 3.11.4

[JelleZijlstra]

This is correct behavior as specified by PEP 561. See python/typing#1333 for discussion of how to change the spec.