Using setuptools.extern.importlib_metadata.EntryPoints.names is incompatible with older versions of importlib_metadata and/or importlib.metadata

[abravalheri]

importlib_metadata.EntryPoints.names was introduced in 3.6.0 and it is currently being used in

setuptools/setuptools/dist.py

Line 538 in 963dbd2

return metadata.distribution('setuptools').entry_points.names

This potentially cause problems when MetaPathFinders in Python 3.8 that use importlib.metadata APIs to implement find_distributions.

This problem was identified in pypa/pyproject-hooks#195 (comment).