# Scala 3.3.8 — 3.3.8 LTS

- Product: Scala (https://whatsnew.fyi/product/scala)
- Vendor: Scala Center
- Date: 2026-06-11
- Version: 3.3.8
- Original notes: https://github.com/scala/scala3/releases/tag/3.3.8
- Permalink: https://whatsnew.fyi/product/scala/releases/3.3.8

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'.

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- **added** — Support for JDK 26
- **added** — New @uncheckedOverride annotation for definitions that may override
- **added** — Trap Ctrl-C in the REPL to clear the prompt if no command is running or ask for confirmation before exiting
- **added** — New '-Yfuture-lazy-vals' option to compile with new lazy val implementation compatible with all JDK 9+
- **added** — Support for local coverage on and off with // $COVERAGE-OFF$ and // $COVERAGE-ON$ markers
- **changed** — Make coverage more similar to Scala 2
- **changed** — Make coverage support incremental compilation
- **fixed** — Check protected parent constructor accesses only occurs in child constructors
- **fixed** — Fix protected constructor access
- **fixed** — Fix deprecation warnings when a symbol is annotated by a deprecated annotation
- **fixed** — Fix Java leading annotation parsing
- **fixed** — Do not allow @targetName on primary constructor
- **fixed** — Cast inline call results to result type, not method type
- **fixed** — Enforce JVM UTF-8 string limits in the backend
- **fixed** — Do not simplify isInstanceOf if unrelated types might be subtypes at run-time
- **fixed** — Fix generic signatures for mixin forwarders conflicting type parameter names
- **fixed** — Fix infinite loop with bad section ends in TastyHeaderUnpickler
- **fixed** — Skip module-info.class files during REPL tab-completion
- **fixed** — Fix for empty ClassPath attribute in one or more classpath jars causing crash
- **fixed** — Fix named arguments evaluation order with by-name parameters

#### Highlights of the release

- Support for JDK 26 [#24430](https://github.com/scala/scala3/pull/24430)
- Multiple coverage improvement to make it on par with Scala 2 support including
  `// $COVERAGE-OFF$` and `// $COVERAGE-ON$` markers.
- New @uncheckedOverride annotation for definitions that may override.
  [#24545](https://github.com/scala/scala3/pull/24545)
- Trap Ctrl-C in the REPL: if no command is running clear the prompt, if some
  command is running ask for confirmation before exiting.
  [#24127](https://github.com/scala/scala3/pull/24127)
- Numerous linting and presentation compiler improvements and fixes.
- New '-Yfuture-lazy-vals' options that allows to compile with new lazy val
  implementation compatible with all JDK 9+
  [#637](https://github.com/scala/scala3-lts/pull/637)

#### Other changes and fixes

##### Access modifiers

- Check protected parent constructor accesses only occurs in child constructors
  [#25511](https://github.com/scala/scala3/pull/25511)
- Fix protected constructor access
  [#25523](https://github.com/scala/scala3/pull/25523)

##### Annotations

- Improve ref check of constructors
  [#24342](https://github.com/scala/scala3/pull/24342)
- Also copy param annots at mixin
  [#24916](https://github.com/scala/scala3/pull/24916)
- Named arg may be deprecatedName
  [#21588](https://github.com/scala/scala3/pull/21588)
- Fix: emit deprecation warnings when a symbol is annotated by a deprecated
  annotation [#23906](https://github.com/scala/scala3/pull/23906)
- Fix #20063: Java leading annotation parsing
  [#25503](https://github.com/scala/scala3/pull/25503)
- Accommodate adapted Scala 2 annotation value
  [#17516](https://github.com/scala/scala3/pull/17516)
- Regression test for #3403 [#25521](https://github.com/scala/scala3/pull/25521)
- Fix: do not allow `@targetName` on primary constructor too
  [#24682](https://github.com/scala/scala3/pull/24682)
- Add `@uncheckedOverride` annotation for definitions that may override
  [#24545](https://github.com/scala/scala3/pull/24545)

##### Backend

- Chore: add regression test for #4528
  [#24663](https://github.com/scala/scala3/pull/24663)
- Cast inline call results to result type, not method type
  [#25111](https://github.com/scala/scala3/pull/25111)
- Regression tests for #25 [#25536](https://github.com/scala/scala3/pull/25536)
- Enforce JVM UTF-8 string limits in the backend
  [#25300](https://github.com/scala/scala3/pull/25300)
- Do not simplify isInstanceOf if unrelated types might be subtypes at run-time
  [#25535](https://github.com/scala/scala3/pull/25535)
- Adjust purity of trait with lazy member
  [#23788](https://github.com/scala/scala3/pull/23788)
- Use `Objects.equals` in translating `==`
  [#25314](https://github.com/scala/scala3/pull/25314)
- Fix generic signatures for mixin forwarders conflicting type parameter names
  [#24567](https://github.com/scala/scala3/pull/24567)
- No mixin forwarder when ancestor is sealed
  [#23482](https://github.com/scala/scala3/pull/23482)
- Simplify JVM interface list emission, remove a mini-phase
  [#25203](https://github.com/scala/scala3/pull/25203)
- Chore: optimize lazy val with power of two
  [#22428](https://github.com/scala/scala3/pull/22428)
- Fix infinite loop with bad section ends in TastyHeaderUnpickler
  [#25676](https://github.com/scala/scala3/pull/25676)
- Fix TastyPrinter's JAR-walking logic to include subdirectories
  [#25678](https://github.com/scala/scala3/pull/25678)

##### Classpath

- Skip `module-info.class` files during REPL tab-completion
  [#24838](https://github.com/scala/scala3/pull/24838)
- Fix for #22461 Empty ClassPath attribute in one or more classpath jars causes
  crash [#22462](https://github.com/scala/scala3/pull/22462)

##### Coverage

- Make coverage more similar to the one in Scala 2
  [#23722](https://github.com/scala/scala3/pull/23722)
- Fix #25555: Preserve singleton precision during sc

_[Truncated at 4000 characters — full notes: https://github.com/scala/scala3/releases/tag/3.3.8]_