pip check does not check extra requirements

[augurar]

• Pip version: 9.0.1
• Python version: Python 2.7.3
• Operating System: Ubuntu 12.04.5 LTS

Description:

Based on the description pip check is intended to check for unsatisfied dependencies in installed packages. However, this does not seem to catch dependency issues related to extras.

Reproducing the issue:

Create packages a, b, c, and d.

.
├── a
│   ├── a
│   └── __init__.py
│   └── setup.py
├── b
│   ├── b
│   │   └── __init__.py
│   └── setup.py
├── c
│   ├── c
│   │   └── __init__.py
│   └── setup.py
└── d
    ├── d
    │   └── __init__.py
    └── setup.py

from setuptools import setup, find_packages

setup(
    name="a",
    version="1.0",
    packages=find_packages(),
)

from setuptools import setup, find_packages

setup(
    name="b",
    version='1.0',
    packages=find_packages(),
    extras_require={
        'a': ['a'],
    },
)

from setuptools import setup, find_packages

setup(
    name="c",
    version="1.0",
    packages=find_packages(),
    install_requires=[
        'b',
    ],
)

from setuptools import setup, find_packages

setup(
    name="d",
    version="1.0",
    packages=find_packages(),
    install_requires=[
        'b[a]',
    ],
)

Create dists for all four packages and install to a local pypi. Then (assuming the local pypi is running on localhost port 8080):

$ pip install -i http://localhost:8080 c d
$ pip uninstall a

Now we have an issue, since c --> b[a] --> a, but a is not installed. However, pip check does not catch this issue.

$ pip check
No broken requirements found.

The following script detects the problem:

import pip
import pkg_resources

pkg_resources.require(str(dep.as_requirement())
                      for dep in pip.get_installed_distributions())

$ python check_dependencies.py 
Traceback (most recent call last):
  File "check_dependencies.py", line 5, in <module>
    for dep in pip.get_installed_distributions())
  File ".../venv/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 963, in require
    needed = self.resolve(parse_requirements(requirements))
  File ".../venv/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 849, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'a; extra == "a"' distribution was not found and is required by b

[xavfernandez]

Duplicate of #4086

[augurar]

@xavfernandez Agreed, sorry. Closing.