Release 19.2

Released v19.1.1

- Restore ``pyproject.toml`` handling to how it was with pip 19.0.3 to prevent
  the need to add ``--no-use-pep517`` when installing in editable mode.
- Fix a regression that caused `@` to be quoted in pypiserver links.
  This interfered with parsing the revision string from VCS urls.

Released v19.1

Features
--------

- Configuration files may now also be stored under ``sys.prefix``.
- Avoid creating an unnecessary local clone of a Bazaar branch when exporting.
- Include in pip's User-Agent string whether it looks like pip is running
  under CI.
- A custom (JSON-encoded) string can now be added to pip's User-Agent
  using the ``PIP_USER_AGENT_USER_DATA`` environment variable.
- For consistency, passing ``--no-cache-dir`` no longer affects whether wheels
  will be built.  In this case, a temporary directory is used.
- Command arguments in ``subprocess`` log messages are now quoted using
  ``shlex.quote()``.
- Prefix warning and error messages in log output with `WARNING` and `ERROR`.
- Using ``--build-options`` in a PEP 517 build now fails with an error,
  rather than silently ignoring the option.
- Error out with an informative message if one tries to install a
  ``pyproject.toml``-style (PEP 517) source tree using ``--editable`` mode.
- When downloading a package, the ETA and average speed now only update once per second
  for better legibility.

Bug Fixes
---------

- The stdout and stderr from VCS commands run by pip as subprocesses (e.g.
  ``git``, ``hg``, etc.) no longer pollute pip's stdout.
- Fix handling of requests exceptions when dependencies are debundled.
- Make pip's self version check avoid recommending upgrades to prereleases if the
  currently-installed version is stable.
- Fixed crash when installing a requirement from a URL that comes from a
  dependency without a URL.
- Improve handling of file URIs: correctly handle `file://localhost/...` and don't
  try to use UNC paths on Unix.
- Fix ``utils.encoding.auto_decode()`` ``LookupError`` with invalid encodings.
  ``utils.encoding.auto_decode()`` was broken when decoding Big Endian BOM
  byte-strings on Little Endian or vice versa.
- Fix incorrect URL quoting of IPv6 addresses.
- Redact the password from the extra index URL when using ``pip -v``.
- The spinner no longer displays a completion message after subprocess calls
  not needing a spinner. It also no longer incorrectly reports an error after
  certain subprocess calls to Git that succeeded.
- Fix the handling of editable mode during installs when ``pyproject.toml`` is
  present but PEP 517 doesn't require the source tree to be treated as
  ``pyproject.toml``-style.
- Fix ``NameError`` when handling an invalid requirement.

Vendored Libraries
------------------

- Updated certifi to 2019.3.9
- Updated distro to 1.4.0
- Update progress to 1.5
- Updated pyparsing to 2.4.0
- Updated pkg_resources to 41.0.1 (via setuptools)

Improved Documentation
----------------------

- Make dashes render correctly when displaying long options like
  ``--find-links`` in the text.

Release 19.0.3

Release 19.0.2

Release 19.0.1

Release 19.0

Release 18.0

Released v9.0.3

* Fix an error where the vendored requests was not correctly containing itself
  to only the internal vendored prefix.

* Restore compatability with 2.6.

Released v9.0.2

* Fallback to using SecureTransport on macOS when the linked OpenSSL is too old
  to support TLSv1.2.

Released v9.0.1

* Correct the deprecation message when not specifying a --format so that it
  uses the correct setting name (``format``) rather than the incorrect one
  (``list_format``) (:issue:`4058`).

* Fix ``pip check`` to check all available distributions and not just the
  local ones (:issue:`4083`).

* Fix a crash on non ASCII characters from `lsb_release` (:issue:`4062`).

* Fix an SyntaxError in an an used module of a vendored dependency
  (:issue:`4059`).

* Fix UNC paths on Windows (:issue:`4064`).

Released v9.0.0

* **BACKWARD INCOMPATIBLE** Remove the attempted autodetection of requirement
  names from URLs, URLs must include a name via `#egg=`.

* **DEPRECATION** ``pip install --egg`` have been deprecated and will be
  removed in the future. This "feature" has a long list of drawbacks where it
  breaks almost all of pip's other features in subtle and hard to diagnose
  ways.

* Add a pip check command to check installed packages dependencies
  (:pull:`3750`).

* Added option to allow user to abort pip operation if file/directory exists

* Added Appveyor CI

* Uninstall existing packages when performing an editable installation of
  the same packages (:issue:`1548`).

* Pip show is less verbose by default. `--verbose` prints multiline fields.
  (:pull:`3858`).

* Added optional column formatting to ``pip list`` (:issue:`3651`).

* Add `--not-required` option to ``pip list`` to list packages that are
  not dependencies of other packages.

* Fix the build on systems with symlinked /tmp directory for custom
  builds such as numpy (:pull:`3701`).

* Fix regression in pip freeze: when there is more than one git remote,
  priority is given to the remote named origin (:pull:`3708`, :issue:`3616`).

* Fix crash when calling pip freeze with invalid requirement installed
  (:pull:`3704`, :issue:`3681`).

* Support multiple --requirement files in pip freeze (:pull:`3703`).

* Implementation of pep-503 ``data-requires-python``. When this field is
  present for a release link, pip will ignore the download when
  installing to a Python version that doesn't satisfy the requirement.

* Pip wheel now works on editable packages too (it was only working on
  editable dependencies before); this allows running pip wheel on the result
  of pip freeze in presence of editable requirements (:pull:`3695`,
  :issue:`3291`).

* Load credentials from .netrc files (:pull:`3715`, :issue:`3569`).

* Add --platform, --python-version, --implementation and --abi parameters to
  ``pip download``. These allow utilities and advanced users to gather
  distributions for interpreters other than the one pip is being run on.
  (:pull:`3760`)

* Skip scanning virtual environments even when venv/bin/python is a dangling
  symlink.

* Added pip completion support for fish shell.

* Fix problems on Windows on Python 2 when username or hostname contains
  non-ASCII characters (:issue:`3463`, :pull:`3970`, :pull:`4000`).

* Use git fetch --tags to fetch tags in addition to everything else that
  is normally fetched; this is necessary in case a git requirement url
  points to a tag or commit that is not on a branch (:pull:`3791`)

* Normalize package names before using in ``pip show`` (:issue:`3976`)

* Raise when Requires-Python do not match the running version and add
  ``--ignore-requires-python`` option as escape hatch (:pull:`3846`).

* Report the correct installed version when performing an upgrade in some
  corner cases (:issue:`2382`)

* Add -i shorthand for --index flag in pip search

* Do not optionally load C dependencies in requests (:issue:`1840`,
  :issue:`2930`, :issue:`3024`)

* Strip authentication from SVN url prior to passing it into svn
  (:pull:`3697`, :issue:`3209`).

* Also install in platlib with --target option (:pull:`3694`, :issue:`3682`).

* Restore the ability to use inline comments in requirements files passed to
  ``pip freeze`` (:issue:`3680`).

* Deprecate --default-vcs option (:issue:`4052`).

Released v8.1.2

* Fix a regression on systems with uninitialized locale (:issue:`3575`).
* Use environment markers to filter packages before determining if a
  required wheel is supported. Solves (:issue:`3254`).
* Make glibc parsing for `manylinux1` support more robust for the variety of
  glibc versions found in the wild (:issue:`3588`).
* Update environment marker support to fully support PEP 508 and legacy
  environment markers (:issue:`3624`).
* Always use debug logging to the ``--log`` file (:issue:`3351`).
* Don't attempt to wrap search results for extremely narrow terminal windows
  (:issue:`3655`).

Released v8.1.1

* Fix regression with non-ascii requirement files on Python 2 and add support
  for encoding headers in requirement files (:issue:`3548`, :pull:`3547`).

Released v8.1.0

* Implement PEP 513, which adds support for the manylinux1 platform tag,
  allowing carefully compiled binary wheels to be installed on compatible Linux
  platforms.

* Allow wheels which are not specific to a particular Python interpreter but
  which are specific to a particular platform (:issue:`3202`).

* Fixed an issue where ``call_subprocess`` would crash trying to print debug
  data on child process failure (:issue:`3521`, :pull:`3522`).

* Exclude the wheel package from the `pip freeze` output (like pip and setuptools).
  :issue:`2989`.

* Allow installing modules from a subdirectory of a vcs repository
  in non-editable mode (:issue:`3217`, :pull:`3466`).

* Make pip wheel and pip download work with vcs urls with subdirectory option
  (:pull:`3466`).

* Show classifiers in ``pip show``.

* Show PEP376 Installer in ``pip show`` (:issue:`3517`).

* Unhide completion command (:pull:`1810`).

* Show latest version number in ``pip search`` results (:pull:`1415`).

* Decode requirement files according to their BOM if present (:pull:`3485`,
  :issue:`2865`).

* Fix and deprecate package name detection from url path (:issue:`3523` and
  :pull:`3495`).

* Correct the behavior where interpreter specific tags (such as cp34) were
  being used on later versions of the same interprter instead of only for that
  specific interpreter (:issue:`3472`).

* Fix an issue where pip would erroneously install a 64 bit wheel on a 32 bit
  Python running on a 64 bit OS X machine.

* Do not assume that all git repositories have an origin remote.

* Correctly display the line to add to a requirements.txt for an URL based
  dependency when ``--require-hashes`` is enabled.