Mercurial 3.8 release

Features

hg update and other commands that can perform update (such as hg pull -u) now warn about other topological heads
cHg has been added
hg update now updates to the tip-most changeset on the same topological branch. Before, it would update to the tip-most changeset, possibly on a different topological head
Hints on how to continue interrupted commands are now printed (e.g. hg resolve -m will now tell you to run hg rebase --continue or hg histedit --continue)
The experimental automv extension has been added. This extension attempts to detect file copes and renames automatically.
The 3rd party hgwatchman extension has been imported as the fsmonitor extension. This extension uses filesystem watching to make commands like hg status significantly faster on large repositories.
hg rebase now chooses its default destination the same way hg merge does
hg pull -u now activates a bookmark if the has a bookmark
hg pull -u now deactivates a bookmark if the destination doesn't match the existing bookmark
Improved edge styles in graph log. d7af9b4ae7dd
User template keywords and functions can be defined in [templatealias] section.
It's now possible to push the active bookmark using hg push -B ..

This release includes many improvements, including (but not limited to):

performance of copy detection during rebases has been improved, potentially leading to faster rebase execution
performance of hg log -f <file> has been improved
syntax errors in loaded extensions are now handled better
hg update on Windows should now be up to 4x faster
JSON encoding should now be proper UTF-8 for all inputs
Performance of the - revset operator has been improved
The blackbox extension now logs more data
"hgext" is now a Python namespace package
revsets accessing changelog data (commit messages, authors, dates) are now 10-15% faster
hg.exe built in MinGW will now link against the proper Python DLL

A full overview is available on WhatsNew.