pip no longer lists available version on fail

[talwrii]

Environment

• pip version: 20.3b1 (and new version)
• Python version: Python 3.7.9
• OS: Docker image (ubuntu running on mac)

Description
pip install pip== The defacto standard for listing packages no longer lists available versions. There appears to be no way list available packages from the command line without using a custom script. (see https://stackoverflow.com/questions/47955263/what-are-data-classes-and-how-are-they-different-from-common-classes)

Expected behavior
I expected pip install pip== to list available versions of a package. If it will not going forward, you might consider providing a way to list available packages (note that yolk3k does not work) perhaps similar to the pip install -v that you appear to have removed historically.

How to Reproduce

docker run python:3.7 bash -c 'pip install pip==20.2.4; pip install pip=='
Collecting pip==20.2.4
  Downloading pip-20.2.4-py2.py3-none-any.whl (1.5 MB)
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 20.2.3
    Uninstalling pip-20.2.3:
      Successfully uninstalled pip-20.2.3
Successfully installed pip-20.2.4
ERROR: Could not find a version that satisfies the requirement pip== (from versions: 0.2, 0.2.1, 0.3, 0.3.1, 0.4, 0.5, 0.5.1, 0.6, 0.6.1, 0.6.2, 0.6.3, 0.7, 0.7.1, 0.7.2, 0.8, 0.8.1, 0.8.2, 0.8.3, 1.0, 1.0.1, 1.0.2, 1.1, 1.2, 1.2.1, 1.3, 1.3.1, 1.4, 1.4.1, 1.5, 1.5.1, 1.5.2, 1.5.3, 1.5.4, 1.5.5, 1.5.6, 6.0, 6.0.1, 6.0.2, 6.0.3, 6.0.4, 6.0.5, 6.0.6, 6.0.7, 6.0.8, 6.1.0, 6.1.1, 7.0.0, 7.0.1, 7.0.2, 7.0.3, 7.1.0, 7.1.1, 7.1.2, 8.0.0, 8.0.1, 8.0.2, 8.0.3, 8.1.0, 8.1.1, 8.1.2, 9.0.0, 9.0.1, 9.0.2, 9.0.3, 10.0.0b1, 10.0.0b2, 10.0.0, 10.0.1, 18.0, 18.1, 19.0, 19.0.1, 19.0.2, 19.0.3, 19.1, 19.1.1, 19.2, 19.2.1, 19.2.2, 19.2.3, 19.3, 19.3.1, 20.0, 20.0.1, 20.0.2, 20.1b1, 20.1, 20.1.1, 20.2b1, 20.2, 20.2.1, 20.2.2, 20.2.3, 20.2.4, 20.3b1, 20.3, 20.3.1)
ERROR: No matching distribution found for pip==
WARNING: You are using pip version 20.2.4; however, version 20.3.1 is available.
You should consider upgrading via the '/usr/local/bin/python -m pip install --upgrade pip' command.
--- 20-12-09T17:20:45  1 0:05 tomwright@Toms-MacBook-Pro:/Users/tomwright/bins (:|✔)
docker run python:3.7 bash -c 'pip install pip==20.3b1; pip install pip=='
Collecting pip==20.3b1
  Downloading pip-20.3b1-py2.py3-none-any.whl (1.5 MB)
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 20.2.3
    Uninstalling pip-20.2.3:
      Successfully uninstalled pip-20.2.3
Successfully installed pip-20.3b1
ERROR: Could not find a version that satisfies the requirement pip==
ERROR: No matching distribution found for pip==
WARNING: You are using pip version 20.3b1; however, version 20.3.1 is available.
You should consider upgrading via the '/usr/local/bin/python -m pip install --upgrade pip' command.

[uranusjr]

See #9139