I'm confused about <https://kotlinlang.org/docs/gradle-configure-project.html#gradle-java-toolchains...

# gradle

[mbonnin]

I'm confused about https://kotlinlang.org/docs/gradle-configure-project.html#gradle-java-toolchains-support:

When there is no explicit information about the jvmTarget value in the build script, its default value is null, and the compiler translates it to the default value 1.8. The targetCompatibility equals a current Gradle's JDK version

If the default value is 1.8 , how come targetCompatibility is Gradle's JDK? Is there a difference between jvmTarget and targetCompatibility ?

[tapchicoma]

JavaCompile by default has targetCompatibility value set to current Gradle JDK version, while Kotlin jvmTarget is always 1.8 (but not with Gradle 8.+).

So if you are running Gradle build with JDK 11 - your compiled Java and Kotlin classes will have different class version

[mbonnin]

I'm trying Gradle 8 at the moment

[tapchicoma]

From Gradle 8.0 both Java and Kotlin uses default toolchain (by default same as Gradle JDK) and configure accordingly targetCompatiblity and jvmTarget values

[mbonnin]

I see . But looks like Android still forces java to 8 (but not Kotlin)

[tapchicoma]

before Gradle 8 default toolchain is null leading to such difference

[tapchicoma]

AGP has a bug, wait a sec

[tapchicoma]

Actually bug is linked in the docs )
https://issuetracker.google.com/issues/260059413

[mbonnin]

Ah yes, perfetc!

[mbonnin]

I need a flow chart of jvmTargets 😅

[mbonnin]

Thanks for the insights!

[tapchicoma]

with Gradle 8 and fix in AGP it should be straightforward 😅