Released v6.1.0 * Fixes :issue:`2502`. Upgrades were failing when no potential links were found for dependencies other than the current installation. (:pull:`2538`) * Use a smoother progress bar when the terminal is capable of handling it, otherwise fallback to the original ASCII based progress bar. * Display much less output when `pip install` succeeds, because on success, users probably don't care about all the nitty gritty details of compiling and installing. When `pip install` fails, display the failed install output once instead of twice, because once is enough. (:pull:`2487`) * Upgrade the bundled copy of requests to 2.6.0, fixing CVE-2015-2296. * Display format of latest package when using ``pip list --outdated``. (:pull:`2475`) * Don't use pywin32 as ctypes should always be available on Windows, using pywin32 prevented uninstallation of pywin32 on Windows. (:pull:`2467`) * Normalize the ``--wheel-dir`` option, expanding out constructs such as ``~`` when used (:pull:`2441`). * Display a warning when an undefined extra has been requested. (:pull:`2142`) * Speed up installing a directory in certain cases by creating a sdist instead of copying the entire directory. (:pull:`2535`) * Don't follow symlinks when uninstalling files (:pull:`2552`) * Upgrade the bundled copy of cachecontrol from 0.11.1 to 0.11.2. Fixes :issue:`2481` (:pull:`2595`) * Attempt to more smartly choose the order of installation to try and install dependencies before the projects that depend on them. (:pull:`2616`) * Skip trying to install libraries which are part of the standard library. (:pull:`2636`, :pull:`2602`) * Support arch specific wheels that are not tied to a specific Python ABI. (:pull:`2561`) * Output warnings and errors to stderr instead of stdout. (:pull:`2543`) * Adjust the cache dir file checks to only check ownership if the effective user is root. (:pull:`2396`) * Install headers into a per project name directory instead of all of them into the root directory when inside of a virtual environment. (:pull:`2421`)