Un-deprecate `--process-dependency-links` until an alternative is implemented

• Pip version: 8.1.1
• Python version: 3.5.2
• Operating System: Ubuntu 16.04

Description:

The --process-dependency-links was re-added to pip a while ago because there are a number of valid use-cases for the flag: https://github.com/pypa/pip/pull/1955

For this reason, it should probably be un-deprecated until an implementation of PEP 508/440 is in pip. The dependency_links argument to setuptools’s setup is also still documented and not deprecated: http://setuptools.readthedocs.io/en/latest/setuptools.html#dependencies-that-aren-t-in-pypi

What I’ve run:

$ pip install request --process-dependency-links
Collecting request
  Downloading request-0.0.12.tar.gz
  DEPRECATION: Dependency Links processing has been deprecated and will be removed in a future release.
... 

[ghost]

What’s the proper workflow for this?

Let 's say there’s a library that I need to add a feature to. I fork it on Github. Feature isn’t going to be merged any time soon, so I have a tool that I set to use my Github fork instead of PyPi.

Now all of my users have to add --process-dependency-links when installing my tool with pip, which is a deprecated and even once removed flag?

Is there some option in setup.py that I’m missing or is there really no way around this? It seems like the only viable way to do this is to push up a forked pypi package. That is just going to add to user’s confusion once your pull request does get merged, anyway.

[rgerkin]

I want to leave a small but successful example here for those who first came upon this issue terrified (like me) about what to do with out --process-dependency-links. Using this workflow, my users are now been able to pip install from GitHub or from local sources (not PyPI), or to pip install requirements.txt, or to python setup.py install, and to work on Travis-CI, with pip version 18+, so I think it covers a lot of bases. I hope it is useful to someone, and my apologies if this seems off-topic to others:

In your requirements.txt file, assuming you want people to be able to depend on the GitHub dev branch of package “foo”, e.g.:

scipy>=0.17
matplotlib>=2.0
foo @ git+https://github.com/foo-organization/foo@dev#egg=foo-9999

In your setup.py file:

import os, sys
from setuptools import setup, find_packages

def read_requirements():
    """Parse requirements from requirements.txt."""
    reqs_path = os.path.join('.', 'requirements.txt')
    with open(reqs_path, 'r') as f:
        requirements = [line.rstrip() for line in f]
    return requirements

setup(
    ..., # Other stuff here
    install_requires=read_requirements(),
    )

Some would say that conflating install_requires and requirements.txt is ill-advised, and for a released version, I agree, but I think this works well for development.