== New Features == * clonebundles can be annotated with the expected memory requirements using the `REQUIREDRAM` option. This allows clients to skip bundles created with large zstd windows and fallback to larger, but less demanding bundles. * The `phabricator` extension now provides more functionality of the arcanist CLI like changing the status of a differential. * Phases processing is much faster, especially for repositories with old non-public changesets. == New Experimental Features == * The core of some hg operations have been (and are being) implemented in rust, for speed. `hg status` on a repository with 300k tracked files goes from 1.8s to 0.6s for instance. This has currently been tested only on linux, and does not build on windows. See rust/README.rst in the mercurial repository for instructions to opt into this. == Backwards Compatibility Changes == * Mercurial now requires at least Python 2.7.9 or a Python version that backported modern SSL/TLS features (as defined in PEP 466), and that Python was compiled against a OpenSSL version supporting TLS 1.1 or TLS 1.2 (likely this requires the OpenSSL version to be at least 1.0.1). * The `hg perfwrite` command from contrib/perf.py was made more flexible and changed its default behavior. To get the previous behavior, run `hg perfwrite --nlines=100000 --nitems=1 --item='Testing write performance' --batch-line`. == Internal API Changes == * logcmdutil.diffordiffstat() now takes contexts instead of nodes. * The `mergestate` class along with some related methods and constants have moved from `mercurial.merge` to a new `mercurial.mergestate` module. * The `phasecache` class now uses sparse dictionaries for the phase data. New accessors are provided to detect if any non-public changeset exists (`hasnonpublicphases`) and get the correponsponding root set (`nonpublicphaseroots`).