Save your Scala apps from the LazyValpocalypse, with Łukasz Biały!

Łukasz Biały explains the upcoming changes to lazy vals in JDK 26 and how Scala 3 is adapting to avoid issues.

Learn more about what's changing with Lazy Vals in JDK 26, why it's a danger for Scala 3 applications, and what's being done to avoid a disaster - with today's guest, Łukasz Biały from @VirtusLab! Links: - SIP-20 github.com/scala/improvement-proposals/pull/19 - SIP-20 implementation docs.scala-lang.org/scala3/reference/changed-features/lazy-v… - Implementation of VarHandle-based Lazy Vals in Scala 3.8 github.com/scala/scala3/pull/24109 - Backport to 3.3.8 github.com/scala/scala3-lts/pull/637 - Andrei Kucharavy: Safe Coding with LLMs - Verifiable Scala Silver Bullet [Scala Days 2025] youtube.com/watch?v=XFj5fpx9ta4 I'm on Twitter: twitter.com/kubukoz on GitHub: github.com/kubukoz sometimes stream on Twitch: twitch.tv/kubukoz And you can buy me a coffee if you want: ko-fi.com/kubukoz You can find Łukasz on: - X/Twitter: x.com/lukasz_bialy - Scala Space podcast @scalaspace Chapters: 00:00 Intro 00:00 Introduction 01:31 The problem with JDK8 - Unsafe API 03:19 Scala's usage of Unsafe 04:12 SIP-20 and Scala 3's encoding of lazy vals 05:07 A JDK 9 alternative 07:17 Deprecation of Unsafe in the JDK 08:00 How Scala is impacted 09:22 The problem with the Scala LTS ecosystem 11:19 Are we lost? 12:58 The solution - patching the bytecode 14:02 3.3 LTS backport 15:00 The correctness concerns 16:37 The verification pipeline 22:58 How AI was used for the draft 28:52 Showcase 32:22 Verification setup 43:59 Next steps 49:08 Discussion 55:31 Parting words