Why am I getting 'Compose Compiler Gradle plugin is required' in Kotlin 1.9 project?

Question

I’m working on an Android project using Kotlin version 1.9.0, and I'm encountering the following error message when trying to build my project:

Starting in Kotlin 2.0, the Compose Compiler Gradle plugin is required when compose is enabled. See the following link for more information: https://d.android.com/r/studio-ui/compose-compiler

Here is a snippet of my build.gradle file:

allprojects {
buildscript {
    ext.kotlin_version = '1.9.0'
    repositories {
        google()
        mavenLocal()
        mavenCentral()
        maven { url 'https://jitpack.io' }
        maven { url 'https://developer.huawei.com/repo/' }
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:8.5.2'
        classpath "io.realm:realm-gradle-plugin:10.18.0"
        classpath 'com.google.gms:google-services:4.4.2'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:2.0.20"
        classpath 'com.google.firebase:firebase-crashlytics-gradle:3.0.2'
        classpath 'com.huawei.agconnect:agcp:1.9.1.303'
        classpath 'com.huawei.hms.plugin:analytics:5.0.1.300'
        classpath 'androidx.navigation:navigation-safe-args-gradle-plugin:2.8.0'
    }
}
}

android {
   compileOptions {
    coreLibraryDesugaringEnabled true
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

kotlinOptions {
    jvmTarget = JavaVersion.VERSION_1_8.toString()
}

buildFeatures {
    dataBinding = true
    compose = true
}

composeOptions {
    kotlinCompilerExtensionVersion "1.5.14"
}
}

Even though my project is using Kotlin 1.9.0, I still receive the message about the Compose Compiler plugin required for Kotlin 2.0. I have set kotlinCompilerExtensionVersion to "1.5.14" in composeOptions. Why am I getting this error?

Answer 1

This issue is occurring because you are using kotlin version > 2.0.0, and in Kotlin 2.0+, the compose compiler is no longer bundled with kotlin itself. It must be explicitly declared as a plugin.

[versions]
kotlin = "2.1.0"

[plugins]
jetbrains-kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }

so according to official documentation (link) if you are using kotlin version > 2.0.0, you need to add this compose-compiler

in libs.versions.toml

[plugins]
compose-compiler = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }

Add the Compose Compiler plugin in both the project-level and app-level build.gradle.kts files

plugins {
   // Existing plugins
   alias(libs.plugins.compose.compiler) apply false
}

plugins {
   // Existing plugins
   alias(libs.plugins.compose.compiler)
}

Answer 2

For older projects not using Kotlin (*.kts) build scripts and libs.versions.toml but using Kotlin version >= 2.0

First add the classpath in the dependencies section of your root build.gradle file:

dependencies {
    //.. other classpaths
    classpath "org.jetbrains.kotlin.plugin.compose:org.jetbrains.kotlin.plugin.compose.gradle.plugin:$kotlin_version"
}

And then in the build.gradle file for each module using compose, apply the compose compiler plugin like so:

apply plugin: "org.jetbrains.kotlin.plugin.compose"