Can't install zope-component even though it's on PyPI

[wimglenn]

$ pip install zope-component==4.2.0 
Collecting zope-component==4.2.0
  Could not find a version that satisfies the requirement zope-component==4.2.0 (from versions: 4.3.0, 4.4.0, 4.4.1, 4.5)
No matching distribution found for zope-component==4.2.0

Environment

• pip version: 18.1
• Python version: 3.7.1
• OS: Linux

Description

pip can not install zope-component using the canonical name even though it is clearly present in the index --> see https://pypi.org/simple/zope-component/

For some reason, pip is still able to resolve other versions like 4.3.0. Perhaps because they have wheels up, not just sdist.

Expected behavior

pip install zope-component==4.2.0 and pip install zope.component==4.2.0 should do the same thing.

>>> from packaging.utils import canonicalize_name
>>> canonicalize_name('zope.component')
'zope-component'

I just use zope as an example, same issue probably exists for other namespace packages.

[cjerdonek]

I believe this is a duplicate of the following resolved issue: #5870

Feel free to re-open if not.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.