From 2cba3d10f69ba6c4fd9cfdd446c13993c04607bd Mon Sep 17 00:00:00 2001
From: Anders Olsson <anders.e.olsson@gmail.com>
Date: Thu, 10 Sep 2026 07:50:43 +0200
Subject: [PATCH] chore: Release trueskill-tt version 0.9.0

---
 CHANGELOG.md | 71 ++++++++++++++++++++++++++++++++++++++++++++--------
 Cargo.toml   |  2 +-
 2 files changed, 62 insertions(+), 11 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2dbf13d..a438fa3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,65 @@
 
 All notable changes to this project will be documented in this file.
 
+## 0.9.0 - 2026-09-10
+
+### Breaking Changes
+
+- fix!: propagate NaN through the convergence reduction
+- fix!: collapse a drift too small to represent, on a relative threshold
+- fix!: report an unresolvable prediction grid instead of clamping
+- fix!: validate the constructors below HistoryBuilder
+- fix!: seal ConstantDrift's field so gamma can be validated
+- fix!: make the Time generic reachable
+- refactor!: un-export six types that no caller could reach
+- fix!: correct eight wrong `# Errors` sections and seal the error variants
+- fix!: per-key queries report unknown keys instead of a plausible constant
+- fix!: no prediction path answers from a fit it cannot answer from
+- docs!: one name for score noise, and say which of beta/sigma to turn
+- fix!: non_exhaustive on ConvergenceReport, and not on the options structs
+- feat!: prediction and joint queries take borrowed keys
+- feat!: Game is the type you get, and one_v_one returns one
+- feat!: Gaussian's EP operations stop wearing arithmetic's clothes
+- refactor!: retire Index, intern and lookup
+- refactor!: scores_with_noise, and History::quality
+- refactor!: the joint is reached through Joint, not mirrored on History
+- refactor!: K comes first in History, HistoryBuilder and Joint
+- perf!: sparse Cholesky with an AMD ordering for the joint
+- refactor!: typed discriminators for InferenceError
+
+### Bug Fixes
+
+- fix: take quality's determinant ratio in log space
+- fix: keep the truncated variance representable in the far tail
+- fix: route the last three transcendentals through libm, and enforce it
+- fix: make posterior_of reproducible across processes
+- fix: warn on dropped builders and values; stop exporting EP internals
+
+### CI
+
+- ci: measure the runner's own benchmark variance, and fix the joint bench
+
+### Documentation
+
+- docs: document the whole public surface and deny(missing_docs)
+- docs: add a migration guide for 0.9.0, and drop merge noise from the changelog
+
+### Features
+
+- feat: add the missing trait impls and make `#[must_use]` consistent
+- feat: complete the evidence matrix and add current_skills
+- feat: PartialEq on the config types, and pin the public trait impls
+- feat: HistoryBuilder::default_rating_for, a rule instead of a roll call
+
+### Refactor
+
+- refactor: one word per concept
+
+### Testing
+
+- test: scale the ceiling sweep by build profile
+- test: make the determinism test exercise the parallel sweep
+
 ## 0.8.0 - 2026-09-08
 
 ### Breaking Changes
@@ -25,13 +84,9 @@ All notable changes to this project will be documented in this file.
 
 - feat: add EventBuilder::members for per-member configuration
 
-### Other (unconventional)
+### Miscellaneous Tasks
 
-- Merge branch 'fix/ingestion-shape'
-- Merge branch 'feat/convergence-strictness'
-- Merge branch 'fix/non-finite-weights'
-- Merge branch 'test/close-coverage-gaps'
-- Merge branch 'fix/game-boundary'
+- chore: Release trueskill-tt version 0.8.0
 
 ### Testing
 
@@ -47,10 +102,6 @@ All notable changes to this project will be documented in this file.
 
 - chore: Release trueskill-tt version 0.7.0
 
-### Other (unconventional)
-
-- Merge branch 'feat/joint-handle'
-
 ## 0.6.0 - 2026-09-08
 
 ### Breaking Changes
diff --git a/Cargo.toml b/Cargo.toml
index 21e951d..7d76907 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "trueskill-tt"
-version = "0.8.0"
+version = "0.9.0"
 edition = "2024"
 rust-version = "1.85"
 description = "TrueSkill Through Time: Bayesian skill rating that tracks how skill evolves over time, via Gaussian message passing"