# Scala 3.8.4-RC3

- Product: Scala (https://whatsnew.fyi/product/scala)
- Vendor: Scala Center
- Date: 2026-05-26
- Version: 3.8.4-RC3
- Original notes: https://github.com/scala/scala3/releases/tag/3.8.4-RC3
- Permalink: https://whatsnew.fyi/product/scala/releases/3.8.4-rc3
- 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 v1.14.0
- **changed** — Bump coursier to 2.1.25-M25
- **added** — Allow :help syntax for all settings
- **changed** — Improve the logical sources provider
- **added** — Add ErrorMessageID to -Winfer-union warnings
- **added** — Warn if for with many vals and overloaded map
- **added** — Recognize Nullable annotations in explicit nulls
- **fixed** — Fix false-positive pat mat unreachable case warning
- **changed** — Make type arguments to default methods InferredTypeTrees
- **fixed** — Do not overwrite the supertype of non-trait super in Erasure
- **changed** — Move process parse exceptions to sys.error instead of a custom exception
- **fixed** — Fix TastyPrinter's JAR-walking logic to include subdirectories
- **fixed** — Don't pop outermost region when skipping
- **fixed** — Parse HTML properly in Scaladoc
- **fixed** — Context bound always has a span
- **fixed** — Fix infinite loop with bad section ends in TastyHeaderUnpickler
- **fixed** — Don't lookahead from interpolation

#### Backported PRs

- Bump Scala CLI to v1.14.0 (was v1.13.0) [#26065](https://github.com/scala/scala3/pull/26065)
- Bump coursier to 2.1.25-M25 (was 2.1.25-M24) [#26057](https://github.com/scala/scala3/pull/26057)
- Allow `:help` syntax for all settings [#26052](https://github.com/scala/scala3/pull/26052)
- feature: Improve the logical sources provider [#26079](https://github.com/scala/scala3/pull/26079)
- Add ErrorMessageID to -Winfer-union warnings (#25073) [#25249](https://github.com/scala/scala3/pull/25249)
- Warn if for with many vals and overloaded map [#25090](https://github.com/scala/scala3/pull/25090)
- Recognize Nullable annotations in explicit nulls [#25237](https://github.com/scala/scala3/pull/25237)
- Fix false-positive pat mat unreachable case warning [#25978](https://github.com/scala/scala3/pull/25978)
- Make type arguments to default methods InferredTypeTrees [#25852](https://github.com/scala/scala3/pull/25852)
- Do not overwrite the supertype of non-trait super in Erasure [#26081](https://github.com/scala/scala3/pull/26081)
- Move process parse exceptions to sys.error instead of a custom exception [#25675](https://github.com/scala/scala3/pull/25675)
- Ensure mistakes in CI inputs are caught early [#25677](https://github.com/scala/scala3/pull/25677)
- Fix TastyPrinter's JAR-walking logic to include subdirectories [#25678](https://github.com/scala/scala3/pull/25678)
- Don't pop outermost region when skipping [#25738](https://github.com/scala/scala3/pull/25738)
- Parse HTML properly in Scaladoc [#25681](https://github.com/scala/scala3/pull/25681)
- Context bound always has a span [#25809](https://github.com/scala/scala3/pull/25809)
- Fix infinite loop with bad section ends in TastyHeaderUnpickler [#25676](https://github.com/scala/scala3/pull/25676)
- Don't lookahead from interpolation [#25834](https://github.com/scala/scala3/pull/25834)

#### Contributors

Thank you to all the contributors who made this release possible 🎉

According to `git shortlog -sn --no-merges 3.8.4-RC2..3.8.4-RC3` these are:

```
     8	Solal Pirelli
     4	Wojciech Mazur
     3	Som Snytt
     2	Piotr Chabelski
     1	Martin Odersky
     1	Tomasz Godzik
```