How can I apply kotlin compiler 2??

# compiler

[chanjungskim]

How can I apply kotlin compiler 2??

[Jeff Lockhart]

https://kotlinlang.org/docs/whatsnew19.html#try-the-k2-compiler-in-your-project

[chanjungskim]

Is this setup or just need to run this every build?

[Jeff Lockhart]

In the gradle.properties file.

[chanjungskim]

Of course, it's gradle.properties..

[chanjungskim]

I put it in build.gradle.kts(product level). But build speed is still the same..

tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
    kotlinOptions {
        freeCompilerArgs = listOf("-Xallow-kotlin-package", "-P", "kotlin.experimental.tryK2=true")
    }
}

[ephemient]

that's wrong. kotlinc -P is for compiler plugins and options

[chanjungskim]

I am sorry, I don't understand if you say so.. Could you please how to set it in detail?
I just found command line for single kt file with kotlinc -P

[chanjungskim]

tasks
    .withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompilationTask<*>>()
    .configureEach {
        compilerOptions
            .languageVersion
            .set(
                org.jetbrains.kotlin.gradle.dsl.KotlinVersion.KOTLIN_2
            )
    }

Should I set like this in project level?

[chanjungskim]

Hmm. kotlin 1.9 version is maximum. in that case.

[dmitriy.novozhilov]

Should I set like this in project level?

Yes, you can apply changing language version to all KotlinCompilationTasks in your project
OR
you can create gradle.properties file in root of your project and add kotlin.experimental.tryK2=true line to it

[chanjungskim]

@dmitriy.novozhilov Thanks I set it. But I see any build speed improves.
And should I set

ksp.Xskip-metadata-version-check=true
ksp.Xskip-prerelease-check=true
ksp.Xallow-unstable-dependencies=true

like this in the gradle.properties? It doesn't cause anything but also no speed improvement.

[dmitriy.novozhilov]

Can't tell anything about KSP
It's better to ask in #ksp channel

[chanjungskim]

No, I mean the three options.

[dmitriy.novozhilov]

AFAIK those arguments can not be set via properties
You should pass them in freeCompilerArgs in build scripts for kotlinCompile tasks

[chanjungskim]

So, you mean those are not necessary for K2 right?

[dmitriy.novozhilov]

They are needed if you want to compile one of your modules with K1 against dependency which was compiled with K2
If you enabled K2 in the whole project then those can be omitted