Fixed

• Fixed possible error on some combinations of markers.
• Fixed venv detection so that it only uses VIRTUAL_ENV to detect activated virtualenvs.

Fixed

• Fixed the --no-dev option in install not working properly.
• Fixed prereleases being selected even if another constraint conflicted with them.
• Fixed an error when installing current package in development mode if the generated setup.py had special characters.
• Fixed an error in install for applications not following a known structure.
• Fixed an error when trying to retrieve the current environment.
• Fixed debug:info not showing the current project's virtualenv.

Fixed

• Fixed an error when installing from private repositories.
• Fixed an error when trying to move the lock file on Python 2.7.

Fixed

• Fixed an error when license is unspecified.

Added

• Added a brand new installer.
• Added support for multi-constraints dependencies.
• Added a cache version system.
• Added a --lock option to update to only update the lock file without executing operations. (Thanks to @greysteil)
• Added support for the Project-URL metadata.
• Added support for optional scripts.
• Added a --no-dev option to show. (Thanks to @rodcloutier)

Changed

• Improved virtualenv detection and management.
• Wildcard python dependencies are now equivalent to ~2.7 || ^3.4.
• Changed behavior of the resolver for conditional dependencies.
• The install command will now install the current project in editable mode.
• The develop command is now deprecated in favor of install.
• Improved the check command.
• Empty passwords are now supported when publishing.

Fixed

• Fixed a memory leak in the resolver.
• Fixed a recursion error on duplicate dependencies with only different extras.
• Fixed handling of extras.
• Fixed duplicate entries in both sdist and wheel.
• Fixed excluded files appearing in the package_data of the generated setup.py.
• Fixed transitive directory dependencies installation.
• Fixed file permissions for configuration and authentication files.
• Fixed an error in cache:clear for Python 2.7.
• Fixed publishing for the first time with a prerelease.