Patch pip to work without SSL support

[embray]

This fixes a long-standing issue where if Sage is built on a system without OpenSSL support, doing anything with pip will result in it crashing.

This allows pip to work without SSL support. Its functionality is limited--i.e. it can't download anything from PyPI without SSL. But it does have appropriate error-handling in this case, an can still be used to install local packages fine.

This was originally part of #20218 but I am breaking it out to a separate ticket as requested.

The relevant upstream issue is here: pypa/pip#1165

Upstream: Reported upstream. Developers acknowledge bug.

Component: packages: standard

Keywords: pip

Author: Erik Bray

Branch: b18d84d

Reviewer: Jeroen Demeyer

Issue created by migration from https://trac.sagemath.org/ticket/20913

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

b18d84d

Bump pip package patch level

[sagetrac-git]

Changed commit from 71af670 to b18d84d

[jdemeyer]

comment:3

Do you happen to know how this should be tested, i.e. can I "fake" that I don't have SSL?

[embray]

comment:4

Replying to @jdemeyer:

Do you happen to know how this should be tested, i.e. can I "fake" that I don't have SSL?

Sure. For example put a module called ssl.py that does nothing but raise an ImportError somewhere early on your PYTHONPATH. That's how I tested this.

Welcome back, also!

[jdemeyer]

comment:5

Can you add links in the ticket description to the upstream issue?

[jdemeyer]

Reviewer: Jeroen Demeyer

[jdemeyer]

comment:6

Works fine.

[vbraun]

Changed branch from u/embray/pip-ssl-patch to b18d84d

[embray]

Changed commit from b18d84d to none