1.8.1 (unreleased)

Recalculate secondary dependencies between rounds (#378)
Calculated dependencies could be left with wrong candidates when toplevel requirements happen to be also pinned in sub-dependencies (#450)
Fix duplicate entries that could happen in generated requirements.txt (#427)
Gracefully report invalid pip version (#457)
Fix capitalization in the generated requirements.txt, packages will always be lowercased (#452)

1.8.0

Adds support for upgrading individual packages with a new option --upgrade-package. To upgrade a specific package to the latest or a specific version use --upgrade-package <pkg>. To upgrade all packages, you can still use pip-compile --upgrade. (#409)
Adds support for pinning dependencies even further by including the hashes found on PyPI at compilation time, which will be re-checked when dependencies are installed at installation time. This adds protection against packages that are tampered with. (#383)
Improve support for extras, like hypothesis[django]
Drop support for pip < 8

1.7.1

Add --allow-unsafe option (#377)

1.7.0

Add compatibility with pip >= 8.1.2 (#374) Thanks so much, @jmbowman!

1.6.5

Add warning that pip >= 8.1.2 is not supported until 1.7.x is out

1.6.4

Incorporate fix for atomic file saving behaviour on the Windows platform (see #351)

1.6.3

PyPI won't let me upload 1.6.2

1.6.2

Respect pip configuration from pip.{ini,conf}
Fixes for atomic-saving of output files on Windows (see #351)

1.6.1

Minor changes:

pip-sync now supports being invoked from within and outside an activated virtualenv (see #317)
pip-compile: support -U as a shorthand for --upgrade
pip-compile: support pip's --no-binary and --binary-only flags

Fixes:

Change header format of output files to mention all input files

1.6

Major change:

pip-compile will by default try to fulfill package specs by looking at a previously compiled output file first, before checking PyPI. This means pip-compile will only update the requirements.txt when it absolutely has to. To get the old behaviour (picking the latest version of all packages from PyPI), use the new --upgrade option.

Minor changes:

Bugfix where pip-compile would lose "via" info when on pip 8 (see #313)
Ensure cache dir exists (see #315)

1.5

Add support for pip>=8
Drop support for pip<7
Fix bug where pip-sync fails to uninstall packages if you're using the --no-index (or other) flags

1.4.5

Add --no-index flag to pip-compile to avoid emitting --index-url into the output (useful if you have configured a different index in your global ~/.pip/pip.conf, for example)
Fix: ignore stdlib backport packages, like argparse, when listing which packages will be installed/uninstalled (#286)
Fix pip-sync failed uninstalling packages when using --find-links (#298)
Explicitly error when pip-tools is used with pip 8.0+ (for now)

1.4.4

Fix: unintended change in behaviour where packages installed by pip-sync could accidentally get upgraded under certain conditions, even though the requirements.txt would dictate otherwise (see #290)

1.4.3

Fix: add --index-url and --extra-index-url options to pip-sync
Fix: always install using --upgrade flag when running pip-sync

1.4.2

Fix bug where umask was ignored when writing requirement files (#268)

1.4.1

Fix bug where successive invocations of pip-sync with editables kept uninstalling/installing them (fixes #270)

1.4.0

Add command line option -f / --find-links
Add command line option --no-index
Add command line alias -n (for --dry-run)
Fix a unicode issue

1.3.0

Support multiple requirement files to pip-compile
Support requirements from stdin for pip-compile
Support --output-file option on pip-compile, to redirect output to a file (or stdout)

1.2.0

Add CHANGELOG :)
Support pip-sync'ing editable requirements
Support extras properly (i.e. package[foo] syntax)

(Anything before 1.2.0 was not recorded.)