20.3: pip install foo== does not list available versions

[RafalSkolasinski]

Environment

• pip version: 20.3
• Python version: 3.7
• OS: Ubuntu LTS 20.04

Description

After upgrade from 20.1.1 to 20.3 cannot view available versions using pip install foo== trick

$ pip install ml-metadata==                                         
ERROR: Could not find a version that satisfies the requirement ml-metadata==
ERROR: No matching distribution found for ml-metadata==

Expected behavior

It works or message about No matching distribution... tips about new command to view available versions.

$ pip install ml-metadata==           
ERROR: Could not find a version that satisfies the requirement ml-metadata== (from versions: 0.12.0.dev0, 0.13.0.dev0, 0.13.1.dev0, 0.24.0, 0.25.0)
ERROR: No matching distribution found for ml-metadata==

How to Reproduce

Details above.

[uranusjr]

Duplicate to #9139.

[brainwane]

@RafalSkolasinski Thank you for the bug report!