Hey, Community! :wave: Today we've released Kotlin...

# announcements

[Eugene]

Hey, Community! 👋
Today we've released Kotlin 1.4.30 K. More information about it you can find in this blog post. And precisely this release is essential to us, and hope to you. And here is "Why?".

In Kotlin 1.4.30, we've announced the Beta stage of the new JVM IR backed. This article describes what it is and why it's important to enable it. But let me repeat the article's central thesis here: please, switch on the JVM IR backend and build your project. And if you will face any problems, please use the YouTrack link or this Slack channel to submit your concern or ask a question.

This version of the JVM backend compiler becomes a default one since 1.5. So, we need to test it very-very well, and for that, we call the Community for this kind of activity. And we hope you will answer our call.

With love,
Kotlin Team.

[Marc Knaup]

Looking forward for testing the new IR backend 🎉

When can we test the new Kotlin plugin with the latest EAP? There’s no update available yet.

[Eugene]

So soon! We do last preparations together with Google

[Marc Knaup]

How do I know if my build is indeed using the IR compiler?

I’ve set kotlinOptions.useIR = true but want proof that it’s really set up properly 🙂

[Big Chungus]

Congratz on the release, but I must say, it'd make the new compiler much more appealing if you'd support some gradle.properties prop to control it like you do for JS IR. kotlin.jvm.compiler=<legacy|ir>

[Alexey Belkov [JB]]

Marc, try to compile the following code: https://youtrack.jetbrains.com/issue/KT-44703#focus=Comments-27-4668947.0-0. If it crashes the compiler - you're using the new backend!

[Marc Knaup]

Thanks @Alexey Belkov [JB] 😁

[Alexey Belkov [JB]]

Martynas, there is a request: https://youtrack.jetbrains.com/issue/KT-42089. But I'm not sure it's worth implementing now, if the old backend is going to be dropped soon.

[tylerwilson]

Will we need to wait for an update of Arctic Fox to Canary 6 to move up to 1.4.30? I have not seen the plugin update like I did in AS 4.1.2…

[Alexey Belkov [JB]]

Plugin for Arctic Fox is not released yet, as mentioned in the blog post. I guess it will be released a little later.

[gildor]

I would love to try use new IR, but it crashes on our project,
I was able what is causes one of errors (when typealias is not available on the classpath of module which uses another module with this typealias on public API)

And another one still researching, I’m getting “bad class file” for Kotlin SAM for Java classes, “undeclared type variable: R”, so it looks that something to do with Android R file, also it’s a Kapt issue

I hope to find time in my next sprint to reproduce and report it (or only report if will not be able to fix myself)

[Jurriaan Mous]

I have tested it on our project. I expected it to crash in 1.4.30 because of a current IR issue on Kotlin Native. But everything compiled well and all tests ran successfully. I also confirmed with above crash that it was working with the new IR. So good to go for us. 🙂