=================
Deprecations and Removals
-------------------------
- Improve deprecation warning regarding the copying of source trees when installing from a local directory. (`10128 <https://github.com/pypa/pip/issues/10128>`_)
- Suppress location mismatch warnings when pip is invoked from a Python source
tree, so ``ensurepip`` does not emit warnings on CPython ``make install``. (`10270 <https://github.com/pypa/pip/issues/10270>`_)
- On Python 3.10 or later, the installation scheme backend has been changed to use
``sysconfig``. This is to anticipate the deprecation of ``distutils`` in Python
3.10, and its scheduled removal in 3.12. For compatibility considerations, pip
installations running on Python 3.9 or lower will continue to use ``distutils``. (`10358 <https://github.com/pypa/pip/issues/10358>`_)
- Remove the ``--build-dir`` option and aliases, one last time. (`10485 <https://github.com/pypa/pip/issues/10485>`_)
- In-tree builds are now the default. ``--use-feature=in-tree-build`` is now
ignored. ``--use-deprecated=out-of-tree-build`` may be used temporarily to ease
the transition. (`10495 <https://github.com/pypa/pip/issues/10495>`_)
- Un-deprecate source distribution re-installation behaviour. (`8711 <https://github.com/pypa/pip/issues/8711>`_)
Features
--------
- Replace vendored appdirs with platformdirs. (`10202 <https://github.com/pypa/pip/issues/10202>`_)
- Support `PEP 610 <https://www.python.org/dev/peps/pep-0610/>`_ to detect
editable installs in ``pip freeze`` and ``pip list``. The ``pip list`` column output
has a new ``Editable project location`` column, and the JSON output has a new
``editable_project_location`` field. (`10249 <https://github.com/pypa/pip/issues/10249>`_)
- ``pip freeze`` will now always fallback to reporting the editable project
location when it encounters a VCS error while analyzing an editable
requirement. Before, it sometimes reported the requirement as non-editable. (`10410 <https://github.com/pypa/pip/issues/10410>`_)
- ``pip show`` now sorts ``Requires`` and ``Required-By`` alphabetically. (`10422 <https://github.com/pypa/pip/issues/10422>`_)
- Do not raise error when there are no files to remove with ``pip cache purge/remove``.
Instead log a warning and continue (to log that we removed 0 files). (`10459 <https://github.com/pypa/pip/issues/10459>`_)
- When backtracking during dependency resolution, prefer the dependencies which are involved in the most recent conflict. This can significantly reduce the amount of backtracking required. (`10479 <https://github.com/pypa/pip/issues/10479>`_)
- Cache requirement objects, to improve performance reducing reparses of requirement strings. (`10550 <https://github.com/pypa/pip/issues/10550>`_)
- Support editable installs for projects that have a ``pyproject.toml`` and use a
build backend that supports :pep:`660`. (`8212 <https://github.com/pypa/pip/issues/8212>`_)
- When a revision is specified in a Git URL, use git's partial clone feature to speed up source retrieval. (`9086 <https://github.com/pypa/pip/issues/9086>`_)
- Add a ``--debug`` flag, to enable a mode that doesn't log errors and propagates them to the top level instead. This is primarily to aid with debugging pip's crashes. (`9349 <https://github.com/pypa/pip/issues/9349>`_)
- If a host is explicitly specified as trusted by the user (via the --trusted-host option), cache HTTP responses from it in addition to HTTPS ones. (`9498 <https://github.com/pypa/pip/issues/9498>`_)
Bug Fixes
---------
- Present a better error message, when a ``file:`` URL is not found. (`10263 <https://github.com/pypa/pip/issues/10263>`_)
- Fix the auth credential cache to allow for the case in which
the index url contains the username, but the password comes
from an external source, such as keyring. (`10269 <https://github.com/pypa/pip/issues/10269>`_)
- Fix double unescape of HTML ``data-requires-python`` and ``data-yanked`` attributes. (`10378 <https://github.com/pypa/pip/issues/10378>`_)
- New resolver: Fixes depth ordering of packages during resolution, e.g. a dependency 2 levels deep will be ordered before a dependency 3 levels deep. (`10482 <https://github.com/pypa/pip/issues/10482>`_)
- Correctly indent metadata preparation messages in pip output. (`10524 <https://github.com/pypa/pip/issues/10524>`_)
Vendored Libraries
------------------
- Remove appdirs as a vendored dependency.
- Upgrade distlib to 0.3.3
- Upgrade distro to 1.6.0
- Patch pkg_resources to use platformdirs rather than appdirs.
- Add platformdirs as a vendored dependency.
- Upgrade progress to 1.6
- Upgrade resolvelib to 0.8.0
- Upgrade urllib3 to 1.26.7
Improved Documentation
----------------------
- Update links of setuptools as setuptools moved these documents. The Simple Repository link now points to PyPUG as that is the canonical place of packaging specification, and setuptools's ``easy_install`` is deprecated. (`10430 <https://github.com/pypa/pip/issues/10430>`_)
- Create a "Build System Interface" reference section, for documenting how pip interacts with build systems. (`10497 <https://github.com/pypa/pip/issues/10497>`_)