Deferred

fun <A> CoroutineScope.handleErrorWith(fa: Deferred<A>, f: (Throwable) -> Deferred<A>): Deferred<A> =
  async(start = CoroutineStart.LAZY) {
    try {
        coroutineScope {
          fa.await()
        }
    } catch (e: Throwable) {
      f(e).await()
    }
  }

import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.CoroutineStart
import kotlinx.coroutines.Deferred
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.SupervisorJob
import kotlinx.coroutines.async
import kotlinx.coroutines.coroutineScope
import kotlinx.coroutines.plus
import kotlinx.coroutines.runBlocking
import kotlin.test.Test

class Test {

    fun <A> CoroutineScope.handleErrorWith(fa: Deferred<A>, f: (Throwable) -> Deferred<A>): Deferred<A> =
        async(start = CoroutineStart.LAZY) {
            try {
                fa.await()
            } catch (e: Throwable) {
                f(e).await()
            }
        }

    @Test
    fun t() = runBlocking {
        val result =
            with(CoroutineScope(Dispatchers.Default) + SupervisorJob()) {
                handleErrorWith(async(start = CoroutineStart.LAZY) {
                    throw RuntimeException("Boom!")
                }) {
                    async { it.message }
                }

            }

        val r = result.await() //threw RuntimeException("Boom!") but expected String of value "Boom!"
        println(r)
    }
}