indeed, from earlier on that page:

If a coroutine encounters exception other than CancellationException, it cancels its parent with that exception. This behaviour cannot be overridden and is used to provide stable coroutines hierarchies for structured concurrency which do not depend on CoroutineExceptionHandler implementation. The original exception is handled by the parent when all its children terminate.

@octylFractal Setting up the scope without context does invoke the handler which is what led me to try add a context and see what happens

val scope = CoroutineScope( handler )

you have to use SupervisorJob instead

again, it’s incorrect

this is how Job works

it’s just doesn’t work how you expect with Job

did you read official doc? https://github.com/Kotlin/kotlinx.coroutines/blob/master/docs/exception-handling.md

I just want tell you, that there are many unnecessary components in your code and not how it should be used in any real code

For example I can rewrite it like this:

fun main() {
    try {
        runBlocking {
            launch {
                throw Exception()
            }
        }
    } catch(throwable: Exception) {
        println("Exception $throwable")
    }

    println( "main done" )
}

This will be the same code as above that uses coroutines and exception handling properly, how you expect it

also, in your case you use runBlocking which throws exception that impossible prevent without wrapping code inside to try/catch (for regular or suspend code), or without supervisorJob, which is covered in section “Exceptions in supervised coroutines” of this doc