--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/relnotes/5.5	Tue Jul 28 10:19:49 2020 -0700
@@ -0,0 +1,80 @@
+== 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.
+
+ * An experimental config `rewrite.empty-successor` was introduced to control
+   what happens when rewrite operations result in empty changesets.
+
+
+== Bug Fixes ==
+
+ * For the case when connected to a TTY, stdout was fixed to be line-buffered
+   on Python 3 (where it was block-buffered before, causing the process to seem
+   hanging) and Windows on Python 2 (where it was unbuffered before).
+
+ * Subversion sources of the convert extension were fixed to work on Python 3.
+
+ * Subversion sources of the convert extension now interpret the encoding of
+   URLs like Subversion. Previously, there were situations where the convert
+   extension recognized a repository as present but Subversion did not, and
+   vice versa.
+
+ * The empty changeset check of in-memory rebases was fixed to match that of
+   normal rebases (and that of the commit command).
+
+ * The push command now checks the correct set of outgoing changesets for
+   obsolete and unstable changesets. Previously, it could happen that the check
+   prevented pushing changesets which were already on the server.
+
+
+== 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`.
+
+ * The absorb extension now preserves changesets with no file changes that can
+   be created by the commit command (those which change the branch name
+   compared to the parent and those closing a branch head).
+
+
+== 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`).
+
+ * The `stdin`, `stdout` and `stderr` attributes of the `mercurial.pycompat`
+   module were removed. Instead, the attributes of same name from the
+   `mercurial.utils.procutil` module should be used, which provide more
+   consistent behavior across Python versions and platforms.