❗ Kotlin 2.1.20 + Hilt 2.56.1: Unable to read Kotlin metadata due to unsupported metadata kind: null on CoroutineWorker

[javadjafari1]

After updating to Kotlin 2.1.20 and Hilt 2.56.1, I'm getting the following error at compile time:

error: Unable to read Kotlin metadata due to unsupported metadata kind: null. public final class XStatusWorker extends androidx.work.CoroutineWorker {

This happens in a class that uses @HiltWorker with @AssistedInject constructor and also has @Inject lateinit var fields.

import android.content.Context
import androidx.hilt.work.HiltWorker
import androidx.work.CoroutineWorker
import androidx.work.WorkerParameters
import dagger.assisted.Assisted
import dagger.assisted.AssistedInject
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import javax.inject.Inject

@HiltWorker
internal class XWorker @AssistedInject constructor(
    @Assisted context: Context,
    @Assisted params: WorkerParameters,
) : CoroutineWorker(context, params) {

    @Inject
    internal lateinit var localDataSource: XLocalDataSource

    @Inject
    internal lateinit var remoteDataSource: XRemoteDataSource

    override suspend fun doWork(): Result = withContext(Dispatchers.IO) {
        // ...
    }
}

This setup was working fine with Kotlin 2.0.x and Hilt 2.51+, and it broke only after moving to Kotlin 2.1.20.

Repro info:
Kotlin: 2.1.20

AGP: 8.9.1

Hilt: 2.56.1

By the way Im using Kapt not KSP

[danysantiago]

It seems this issue is coming from androidx's Hilt worker extension. Can you use --stacktrace in Gradle command line to confirm this? What version of androidx.hilt.hilt-compiler are you using?

If you explicitly depend on androidx.room:room-compiler-processing:2.7.0 does it fix the issue for you?

[LouisCAD]

Thank you, @danysantiago, adding kapt("androidx.room:room-compiler-processing:2.7.0") to the dependencies fixed the compilation issue!

Will check if it runs fine.

[javadjafari1]

@danysantiago How can I confirm that? What exactly should I look for in the stacktrace?

I'm using version 1.2.0 of androidx.hilt:hilt-compiler.

I also tried the workaround suggested by @LouisCAD, but no luck on my end. (I'm using KSP for Room, so I replaced kapt with ksp.)

For now, I’ve temporarily resolved the compilation issue by downgrading Kotlin to 2.1.10 and KSP to 2.1.10-1.0.30.

[ffgiraldez]

Same issue here.
I use KSP for room and KAPT for Hilt. Upgrading to Kotlin 2.1.20 breaks the build. I need to use kapt.use.k2=false as a workaround

[javadjafari1]

Also, I tried setting ksp.useKSP2=false, but the issue remains.

I’ll try the workaround suggested by @ffgiraldez next and report back.

[javadjafari1]

@ffgiraldez's workaround worked for me too.

[bolebolo]

Hi, I had the same issue as you. I was using:

kapt(libs.hilt.compiler) // for Hilt
ksp(libs.room.compiler.ksp) // for Room

Versions:

Room: 2.7.2
Kotlin: 2.1.21
KSP: 2.1.21-2.0.1
WorkManager: 2.10.2
Hilt Work: 1.2.0

Everything started working properly once I replaced:

kapt(libs.hilt.compiler)
with
ksp(libs.hilt.compiler)

It took me a while to figure out the issue, but it’s finally resolved.

If you must use kapt, the solution provided by @ffgiraldez works as well.

Hope this helps someone in the future!