# Scala 3.8.4-RC2 - Product: Scala (https://whatsnew.fyi/product/scala) - Vendor: Scala Center - Date: 2026-04-22 - Version: 3.8.4-RC2 - Original notes: https://github.com/scala/scala3/releases/tag/3.8.4-RC2 - Permalink: https://whatsnew.fyi/product/scala/releases/3.8.4-rc2 - Labels: Pre-release What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog. Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'. --- - **changed** — Bump Scala CLI to v1.13.0 - **changed** — Bump jackson-* to 3.1.2 - **fixed** — Reject scala.runtime's mutable refs in safe mode - **changed** — Tweak SafeRefs allow list for java.util classes - **changed** — Tune SafeRefs allow list for scala.util classes - **changed** — Require explicit types in assumeSafe definitions in the empty package - **fixed** — Skip checkSafeAnnots for synthetic symbols - **fixed** — Reject News with unsupported Java classes - **fixed** — Improve LambdaTypes handling in Quotes reflect memberType - **fixed** — Enforce isVarPattern for pat var - **fixed** — Do not warn for package object at the top level - **fixed** — Fix -Ymagic-offset-header for DoubleDefinition error and implicitNotFound errors, and remove global unmanaged cache - **fixed** — Fix scalaXml Elem rendering in repl - **fixed** — Fix Ctrl+C handling in the REPL - **fixed** — Fix covariant overrides with separate compilation causing AbstractMethodError at runtime - **added** — Add logical package parsing for sourcepath #### Backported changes - Revert #24431 [#25703](https://github.com/scala/scala3/pull/25703) - Bump Scala CLI to v1.13.0 (was v1.12.5) [#25810](https://github.com/scala/scala3/pull/25810) - Bump `jackson-*` to 3.1.2 (was 2.15.1) [#25785](https://github.com/scala/scala3/pull/25785) - Reject scala.runtime's mutable refs in safe mode [#25749](https://github.com/scala/scala3/pull/25749) - Tweak SafeRefs allow list for java.util classes [#25783](https://github.com/scala/scala3/pull/25783) - Tune SafeRefs allow list for scala.util classes [#25787](https://github.com/scala/scala3/pull/25787) - Require explicit types in assumeSafe definitions in the empty package [#25795](https://github.com/scala/scala3/pull/25795) - Skip checkSafeAnnots for synthetic symbols [#25773](https://github.com/scala/scala3/pull/25773) - Reject News with unsupported Java classes [#25761](https://github.com/scala/scala3/pull/25761) - Improve LambdaTypes handling in Quotes reflect memberType [#25786](https://github.com/scala/scala3/pull/25786) - Pat var must be isVarPattern [#25701](https://github.com/scala/scala3/pull/25701) - Do not warn for package object at the top level [#25826](https://github.com/scala/scala3/pull/25826) - Fix `-Ymagic-offset-header` for `DoubleDefinition` error and `implicitNotFound` errors, and remove global unmanaged cache [#25706](https://github.com/scala/scala3/pull/25706) - Fix #25691: scalaXml Elem rendering in repl [#25781](https://github.com/scala/scala3/pull/25781) - Fix Ctrl+C handling in the REPL [#25782](https://github.com/scala/scala3/pull/25782) - Fix "Scala 3.8.3 compiling covariant overrides with separate compilation causes AbstractMethodError at runtime" [#25659](https://github.com/scala/scala3/pull/25659) - Fix "Fix Ctrl-C Handling in the REPL" [#25835](https://github.com/scala/scala3/pull/25835) - Improve the test for creating protected method accessors for inlines [#25865](https://github.com/scala/scala3/pull/25865) - feature: Add logical package parsing for sourcepath [#25446](https://github.com/scala/scala3/pull/25446) #### Contributors Thank you to all the contributors who made this release possible 🎉 According to `git shortlog -sn --no-merges 3.8.4-RC1..3.8.4-RC2` these are: ``` 5 Wojciech Mazur 4 Martin Odersky 4 Piotr Chabelski 3 Matt Bovel 2 Jan Chyb 2 Li Haoyi 2 Solal Pirelli 2 noti0na1 1 Jakub Warchoł 1 Som Snytt 1 Tomasz Godzik 1 Yichen Xu ```