Exception thrown by deferred.await() within a runBlocking treated as unhandled even after caught

Question

This code:

fun main() {
    runBlocking {
        try {
            val deferred = async { throw Exception() }
            deferred.await()
        } catch (e: E         


        

Answer 1

This can be resolved by slightly altering the code to make the deferred value be executed explicitly using the same CoroutineContext as the runBlocking scope, e.g.

runBlocking {
    try {
        val deferred = withContext(this.coroutineContext) {
            async {
                throw Exception()
            }
        }
        deferred.await()
    } catch (e: Exception) {
        println("Caught $e")
    }
}
println("Completed")

UPDATE AFTER ORIGINAL QUESTION UPDATED

Does this provide what you want:

runBlocking {
    supervisorScope {
        try {
            val a = async {
                delay(1000)
                println("Done after delay")
            }
            val b = async { throw Exception() }
            awaitAll(a, b)
        } catch (e: Exception) {
            println("Caught $e")
            // Optional next line, depending on whether you want the async with the delay in it to be cancelled.
            coroutineContext.cancelChildren()
        }
    }
}

This is taken from this comment which discusses parallel decomposition.