Upgrading Android kotlin version to 1.5.0 throwing error message on build

I experienced the same issue today. Ran the gradle build command with --stacktrace and got a helpful stacktrace which narrowed down the issue to Moshi library.

Caused by: java.lang.IllegalStateException: Could not parse metadata! This should only happen if you're using Kotlin <1.1.
    at com.squareup.moshi.kotlinpoet.metadata.KotlinPoetMetadata.readKotlinClassMetadata(KotlinPoetMetadata.kt:70)
    at com.squareup.moshi.kotlinpoet.metadata.KotlinPoetMetadata.toImmutableKmClass(KotlinPoetMetadata.kt:50)
    at com.squareup.moshi.kotlin.codegen.MoshiCachedClassInspector.toImmutableKmClass(MoshiCachedClassInspector.kt:22)
    at com.squareup.moshi.kotlin.codegen.MetadataKt.targetType(metadata.kt:109)
    at com.squareup.moshi.kotlin.codegen.JsonClassCodegenProcessor.adapterGenerator(JsonClassCodegenProcessor.kt:136)
    at com.squareup.moshi.kotlin.codegen.JsonClassCodegenProcessor.process(JsonClassCodegenProcessor.kt:110)
    at org.jetbrains.kotlin.kapt3.base.incremental.IncrementalProcessor.process(incrementalProcessors.kt:90)
    at org.jetbrains.kotlin.kapt3.base.ProcessorWrapper.process(annotationProcessing.kt:175)
    at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:980)
    ... 41 more

Had to update Moshi to 1.12.0 and that did the trick.

Here’s a changelog for Moshi 1.12.0 that mentions the fix for 1.5.0: https://github.com/square/moshi/blob/master/CHANGELOG.md#version-1120

Issue when it was first reported here: https://github.com/square/moshi/issues/1324

Another issue which mentions the fix here: https://github.com/square/moshi/issues/1337

So I’d suggest you run gradle build command with --stacktrace and figure out which library causes the incompatibility with the kotlinx-metadata-jvm library and update it.