News

Kotlin 1.6 Support in IntelliJ IDEA 2021.3

The two latest versions of IntelliJ IDEA (2021.2 and 2021.3) were released with a bundled Kotlin IDE Plugin based on the previous stable version of the Kotlin compiler. This situation caused a lot of confusion in the community. We would like to apologize for the current situation and answer all of your questions regarding Kotlin support in IntelliJ IDEA to help you plan Kotlin and IDE updates for your projects:

  • When will it be possible to use Kotlin 1.6 in IntelliJ IDEA 2021.3?
  • Will the next versions of IntelliJ IDEA be released with support for the latest stable Kotlin version?
  • Why doesn’t the latest version of IntelliJ IDEA currently support the latest version of Kotlin?
  • Will it be possible to use EAP versions of IntelliJ IDEA with EAP versions of Kotlin?

When will it be possible to use Kotlin 1.6 in IntelliJ IDEA 2021.3?

Will the next versions of IntelliJ IDEA be released with the latest stable Kotlin version support?

All future IntelliJ IDEA versions, starting with 2022.1, will be released simultaneously with the Kotlin IDE Plugin based on the latest stable compiler version.

Why doesn’t the latest version of IntelliJ IDEA currently support the latest version of Kotlin?

The Kotlin plugin code has been moved to the IntelliJ IDEA repository. The plugin is now closer to IntelliJ IDEA, allowing us to simplify development of the IDE plugin. However, the current infrastructure complicates the adoption of newer versions of the Kotlin compiler. The current infrastructure requires managing myriad commits when we update the compiler version for a particular platform or create a new platform version branch for a particular compiler. It is a complex merge that couldn’t be done in parallel, as it required fixing additional problems and thorough testing. All in all, the task took around six weeks to complete.

To mitigate the problems above and ensure they won’t arise again, we’re working in two directions:

  • We are going to make IntelliJ/master depend on a fresh build of the Kotlin compiler instead of a stable one. At least once a month, we’ll advance the Kotlin compiler version in IntelliJ/master and synchronize commits with branches prepared for the IntelliJ Kotlin plugin release.
  • The Kotlin IDE plugin contains a compiler for building Maven and IntelliJ system-based projects. We will un-bundle the compiler and it will be downloaded dynamically according to the Kotlin version in your project settings. As a result, you will no longer have to worry about the installed plugin version at all. See the related YT ticket for details.

Will it be possible to use EAP versions of IntelliJ IDEA with EAP versions of Kotlin?

The EAP version of Kotlin currently works only with the stable version of the IDE. That means that you can’t install the Kotlin EAP version to a IntelliJ IDEA EAP build. We are going to stabilize the process to allow you to use EAP versions of Kotlin with EAP versions of IntelliJ IDEA after completing all of the infrastructure work to have new IntelliJ IDEA releases with support for the latest stable Kotlin version.

Read more

  • Kotlin Plugin Releases – docs
  • New Release Cadence for Kotlin and the IntelliJ Kotlin Plugin – blog post
  • Improved IDE Performance, Better Debugging Experience, and More for Kotlin in IntelliJ IDEA 2021.2 – blog post

Discover more