Hey everybody, I am trying to add Jetpack Compose to my KMM project and specifically the Android app, however it is not cooperating. I get this error:

java.lang.IncompatibleClassChangeError: Found class org.jetbrains.kotlin.ir.declarations.IrModuleFragment, but interface was expected

. I think it has something to do with incompatible versions of Kotlin or some dependency, so I am trying to follow the example given by the KMM sample docs. Does anyone know which direction to look for a fix?

Are you using

kotlinVersion 1.4.20

with the latest

1.0.0-alpha08

compose compiler version?

composeOptions {
    kotlinCompilerVersion = "1.4.20"
    kotlinCompilerExtensionVersion = "1.0.0-alpha08"
}

Yes!

@Joost Van Wynen fwiw I have small KMM project that also uses Jetpack Compose (alpha08) if you want to compare setup https://github.com/joreilly/PeopleInSpace

@John O'Reilly Yes I found that, that is the sample I have been using as a reference so thanks for that! For some reason your version works perfectly and mine doesn't and I cant find any real differences in the gradle files. Anything special you had to keep in mind using Compose with KMM in comparison to a normal Kotlin Android project?

None that I can think of off the top of my head.

Ok great! Thanks for the answers and for the great and clear sample. With all the extra gradle files and configuration it is easy to miss something so I will probably restart and get that organised and sorted.

do you still have

kotlin("android.extensions")

by any chance?

Hmm this is really weird but removing

kotlin("android.extensions")

does fix my problem. My project now builds without a problem. Thanks!!

that's great.....will also remove it from PeopleInSpace shortly as it isn't needed anyway