pip 20.2 release, plus changes coming in 20.3

[Sumana Harihareswara]

On behalf of the Python Packaging Authority, I am pleased to announce 
that we have just released pip 20.2, a new version of pip. You can 
install it by running python -m pip install --upgrade pip.

The highlights for this release are:

    - The beta of the next-generation dependency resolver is available
    - Faster installations from wheel files
    - Improved handling of wheels containing non-ASCII file contents
    - Faster `pip list` using parallelized network operations
    - Installed packages now contain metadata about whether they were
    directly
    requested by the user (PEP 376’s REQUESTED file)

The new dependency resolver is *off by default* because it is *not yet
ready for everyday use*. The new dependency resolver is significantly
stricter and more consistent when it receives incompatible instructions,
and reduces support for certain kinds of constraints files, so some
workarounds and workflows may break. Please test it with the
`--use-feature=2020-resolver` flag. Please see our guide on how to test 
and migrate, and how to report issues
<https://pip.pypa.io/en/latest/user_guide/#changes-to-the-pip-dependency-resolver-in-20-2-2020>.

We are preparing to change the default dependency resolution behavior 
and make the new resolver the default in pip 20.3 (in October 2020).

This release also partially optimizes pip’s network usage during
installation (as part of a Google Summer of Code project by McSinyx
<https://summerofcode.withgoogle.com/projects/#5428041779511296>). 
Please test it with `pip install --use-feature=2020-resolver 
--use-feature=fast-deps` and report bugs to the issue tracker
<https://github.com/pypa/pip/issues/new?template=bug-report.md>. This
functionality is *still experimental* and *not ready for everyday use*.

You can find more details (including deprecations and removals) in the
changelog <https://pip.pypa.io/en/stable/news/>.

As with all pip releases, a significant amount of the work was 
contributed by pip’s user community. Huge thanks to all who have 
contributed, whether through code, documentation, issue reports and/or 
discussion. Your help keeps pip improving, and is hugely appreciated.

Specific thanks go to Mozilla (through its Mozilla Open Source Support
<https://www.mozilla.org/en-US/moss/> Awards) and to the Chan Zuckerberg
Initiative <https://chanzuckerberg.com/eoss/> DAF, an advised fund of
Silicon Valley Community Foundation, for their funding that enabled
substantial work on the new resolver.


-- 
Sumana Harihareswara
pip project manager via contract with PSF
Changeset Consulting
https://changeset.nyc