# Mercurial 6.8 (2024-07-08)

## Mercurial 6.8.2 

This is the last version that supports Python 3.6 and 3.7.

- Compatibility for Python 3.12 and 3.13
- evolution: stop wrongly flagging unrelated part of a split as divergent
- histedit: create state and acquire locks earlier
- copytracing: fix a bug in an edge case in metadata.compute_all_files_changes
- rhg: ignore readonly FS error when saving dirstate
- merge: sort filemap only if requested by the caller
- windows: implement `util.cachestat` to fix numerous dirstate problems
- subrepo: propagate non-default path on outgoing
- import: fix erroneous comparison of str with bytes
- largefiles: fix check that ensures that --all-largefiles is only used locally
- profiling: improve 3.12 error message for calling lsprof twice
- profiling: use "stat" profiler to profile individual request
- module-policy: ignore empty module policy
- relnotes: skip the test if the source repository is not readable
- wireprototypes: fix exception handling code with a bad pytype suppression
- Many more type fixes and improvements
- Improvements to the test suite

## Mercurial 6.8.1 

- Python 3.12: fix an issue between `threading` and `demandimport`
- rhg: expand user and environment variable in paths to ignore in config and
   includes
- `win32mbcs` extension: fix an encoding issue

## Mercurial 6.8 

As usual, a *lot* of patches don't make it to this list.

### New Features or performance improvements 

- Phases have been reworked to improve their general performance
  - revset: stop serializing node when using "%ln"
  - phases: convert remote phase root to node while reading them
  - phases: use revision number in new_heads
  - phases: use revision number in analyze_remote_phases
  - phases: stop using `repo.set` in `remotephasessummary`
  - phases: move RemotePhasesSummary to revision number
  - phases: use revision number in `_pushdiscoveryphase`
  - phases: introduce a performant efficient way to access revision in a set
  - phases: rework the logic of _pushdiscoveryphase to bound complexity
- The Rust working copy code is being used by more places now:
    - matchers: support patternmatcher in rust
    - dirstate: remove the python-side whitelist of allowed matchers
- stream-clone: disable gc for `_entries_walk` duration
- stream-clone: disable gc for the initial section for the v3 format
- postincoming: avoid computing branchhead if no report will be posted
- stream-clone: disable gc for the entry listing section for the v2 format
- perf: allow profiling of more than one run
- perf: run the gc before each run
- perf: start recording total time after warming
- perf: clear vfs audit_cache before each run
- outgoing: rework the handling of the `missingroots` case to be faster
- outgoing: add a simple fastpath when there is no common
- tags-cache: skip the filternode step if we are not going to use it
- tags-cache: directly operate on rev-num warming hgtagsfnodescache
- tags-cache: directly perform a monimal walk for hgtagsfnodescache warming

### New Experimental Features 

- Introduce a new experimental branch cache "v3":
  - branchcache: add more test for the logic around obsolescence and branch heads
  - branchcache: skip entries that are topological heads in the on disk file
  - branchcache: add a "pure topological head" fast path
  - branchcache: allow to detect "pure topological case" for branchmap

### Bug Fixes 

- rust: use `cpython` 0.7.2 crate to add support for Python 3.12
- perf-stream-locked-section: actually use v1 generation when requested
- perf-stream-locked-section: fix the call to the v3 generator
- perf-stream-locked-section: advertise the right version key in the help
- stream: in v3, skip the "size" fast path if the entries have some unknown size
- stream-clone: stop getting the file size of all file in v3
- streamclone: stop listing files for entries that have no volatile files
- perf-stream-consume: use the source repository config when applying
- bundle: do no check the changegroup version if no changegroup is included
- perf: create the temporary target next to the source in stream-consume
- bundlespec: fix the "streamv2" and "streamv3-exp" variant
- push: rework the computation of fallbackheads to be correct
- profiler: flush after writing the profiler output
- base-revsets: use an author that actually exercises a lot of changesets
- hgrc: search XDG_CONFIG_HOME on mac
- clonebundles: add missing newline to legacy response
- narrow: add a test for linkrev computation done during widen
- Multiple fixes to guard against mmap issues
- portability: fix build on Solaris-derived systemd

### Backwards Compatibility Changes 

### Internal API Changes 

### Miscellaneous 

- obsolete: quote the feature name
