Kotlinx.serialization: 0.8.2-rc13 and iOS: error: unresolved reference: serializer

[yuriry]

After migrating from 0.8.1-rc13 to 0.8.2-rc13 compiling iOS project fails with the following error:

> Task :ios:compileDebugIos_arm64KotlinNative
common/src/main/kotlin/com/**/Foo.kt:159:76: error: unresolved reference: serializer
        fun parse(jsonText: String): Foo = JSON.nonstrict.parse(serializer(), jsonText)
                                                                           ^

> Task :ios:compileDebugIos_arm64KotlinNative FAILED

Common and Android sub-projects build fine.

When I remove serializer() call to make it like this

fun parse(jsonText: String): Foo = JSON.nonstrict.parse(jsonText)

the iOS project builds, but I'm getting the same error at runtime I was getting earlier when not passing serializer as the first argument.

The error above occurs when using either ext.kotlin_version = '1.3.0-rc-131' or ext.kotlin_version = '1.3.0-rc-146'. My current list of dependencies is:

buildscript {
    ext.kotlin_version = '1.3.0-rc-146'
    ext.kotlinPluginUrl = "https://dl.bintray.com/kotlin/kotlin-eap"
    ext.kotlinPluginClassPath = "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    ext.kotlinNativeUrl = "https://dl.bintray.com/jetbrains/kotlin-native-dependencies"
    ext.kotlin_native_version = '1.3.0-rc-146'
    ext.kotlinNativeClassPath = "org.jetbrains.kotlin:kotlin-native-gradle-plugin:$kotlin_native_version"

    ext.serializationUrl = "https://kotlin.bintray.com/kotlinx"
    ext.serialization_version = '0.8.2-rc13'
    ext.serializationClasspath = "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"

    ext.android_gradle_version = '3.2.0'
    ext.androidGradleClassPath = "com.android.tools.build:gradle:$android_gradle_version"
}

Any help would be greatly appreciated!

[sandwwraith]

It looks like the plugin hasn't been applied to the compiler. Do you use kotlin-platform-native? How do you connect plugin with the compiler?

[yuriry]

@sandwwraith
I do use 'kotlin-platform-native'

This is the top part of my iOS sub-projecct

buildscript {
    repositories {
        jcenter()
        maven { url kotlinPluginUrl }
        maven { url kotlinNativeUrl }
    }
    dependencies {
        classpath kotlinPluginClassPath
        classpath kotlinNativeClassPath
        classpath serializationClasspath
    }
}

apply plugin: 'kotlin-platform-native'
apply plugin: 'kotlinx-serialization'

repositories {
    jcenter()
    maven { url kotlinPluginUrl }
    maven { url serializationUrl }
}

My top-level configuration that does not work with this iOS sub-project is in my original post

The top-level configuration that works with this iOS sub-project is this:

buildscript {
    ext.kotlin_version = '1.3.0-rc-57'
    ext.kotlinPluginUrl = "https://dl.bintray.com/kotlin/kotlin-eap"
    ext.kotlinPluginClassPath = "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    ext.kotlinNativeUrl = "https://dl.bintray.com/jetbrains/kotlin-native-dependencies"
    ext.kotlin_native_version = '0.9.2'
    ext.kotlinNativeClassPath = "org.jetbrains.kotlin:kotlin-native-gradle-plugin:$kotlin_native_version"

    ext.serializationUrl = "https://kotlin.bintray.com/kotlinx"
    ext.serialization_version = '0.8.1-rc13'
    ext.serializationClasspath = "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"

    ext.android_gradle_version = '3.2.0'
    ext.androidGradleClassPath = "com.android.tools.build:gradle:$android_gradle_version"
}

For my working iOS sub-project I use mavenLocal() instead of maven { url serializationUrl }, and the commit that is used to publish serialization library locally is 7a7ebe94afdc930e751af9c095edb0c5fc8338a8 (to workaround the main thread related problem)

As soon as I switch to ext.serialization_version = '0.8.2-rc13', I get compiler version problem (either with maven { url serializationUrl } or with mavenLocal() in my iOS sub-project). But when I upgrade the kotlin_version to 1.3.0-rc-131 or 1.3.0-rc-146 I get this problem.

I'm not sure why the plugin hasn't been applied to the compiler. The only thing I did to run into the problem is to upgrade serialization to '0.8.2-rc13' and to bump up kotlin_version to 1.3.0-rc-146.

[yuriry]

@sandwwraith
I created a test project that reproduces the problem, could you please take a look? The line that fails to compile is in Foo.kt

If you change the version information in gradle.properties to

kotlin_version=1.3.0-rc-57
kotlin_native_version=0.9.2
serialization_version=0.8.1-rc13
android_gradle_version=3.2.0

the compilation succeeds.

Please let me know if you need more information.
P.S. Reducing Foo to a bare minimum still reproduced the problem.

[yuriry]

@sandwwraith Have you had a chance to look at the sample project?

[sandwwraith]

@yuriry Yes, it reproduces the problem and I'm investigating it

[sandwwraith]

It seems that the last release of Kotlin/Native gradle plugin for some reason does not add -XPlugin option to compiler. For a workaround, you can pass it manually, as here: https://github.com/sandwwraith/KotlinSerializationPlayground/blob/native_preview/native/build.gradle#L49

[yuriry]

@sandwwraith Thank you for the workaround, it works!

[sandwwraith]

Ok, so as explained in the linked issue, kotlin-platform-native now shades kotlin plugin inside, so all compiler plugins are also shaded and have different ids. To use the plugin with k/n 0.9.3 and library 0.8.2, use line apply plugin: 'kotlinx-serialization-native' in native modules. (this is applicable only to kotlin-platform-native, kotlin-multiplatform works as usual). I've updated the docs: https://github.com/Kotlin/kotlinx.serialization/commit/4ae3d34a05616d6542eca2b88afc7e30f9a0d9b6

I'm closing this now since it is a problem in K/N which has separate ticket.

[tttzof351]

Same question, but my project structure without build.gradle in ios project like https://github.com/JetBrains/kotlin-examples/tree/master/tutorials/mpp-iOS-Android

So, how I can pass -XPlugin for this situation ?

[sandwwraith]

For kotlin-multiplatform plugin you can use usual apply plugin: 'kotlinx-serialization' line. Or do you experience another issue?

[sandwwraith]

@tttzof351 Or maybe https://github.com/Kotlin/kotlinx.serialization/issues/264#issuecomment-439840968 would help you?