diff --git a/_posts/2024-08-23-release-notes-3.4.3.md b/_posts/2024-08-23-release-notes-3.4.3.md index 805c3b80f..739bed625 100644 --- a/_posts/2024-08-23-release-notes-3.4.3.md +++ b/_posts/2024-08-23-release-notes-3.4.3.md @@ -5,10 +5,15 @@ title: "Scala 3.4.3 is now available!" --- Scala 3.4.3 is now available! -The hotfix version 3.4.3 is recommended for library authors who cannot or do not want Scala 3.5 upgrade, but want to keep their forward and backward binary compatibility. We expect that only a few library authors will be affected, as most library authors are using the Scala 3.3 LTS series. Staying on LTS is our standard recommendation for library authors. +The hotfix version 3.4.3 is recommended for library authors who cannot or do not want Scala 3.5 upgrade, but want to keep their forward and backward binary compatibility. This release reverts changes introduced in Scala 3.4.2 that led to binary incompatibility of match types produced by the compiler. You can read about this issue in [Scala 3 repository](https://github.com/scala/scala3/issues/21258). The new behaviour would be restored in some next major version (probably 3.6) after being well described and probably introducing a warning for the users. +We expect that only a few library authors will be affected, because: + +- most library authors are using the Scala 3.3 LTS series. Staying on LTS is our standard recommendation for library authors. +- the issue is specific to match types that are exposed in APIs + We recommend authors of Scala 3 libraries that use match types in their APIs to set up [TASTy MiMA](https://github.com/scalacenter/tasty-mima) checks as the extension to classic bytecode-based MiMa binary compatibility assertions. For a full list of changes and contributor credits, please refer to the [release notes](https://github.com/scala/scala3/releases/tag/3.4.3).