test-fatals.scala

//> using scala "3.3.0"

import scala.concurrent.*, ExecutionContext.Implicits.global, duration.*
import scala.util.boundary, boundary.*

def runsOnAnotherThread(msg: String): Future[Unit] = 
  Future:
    println(s"This: $msg runs on ${Thread.currentThread.getName}")

def testFatals(): Future[String] = 
  boundary:
    for
      _ <- runsOnAnotherThread("first")
      _ = throw OutOfMemoryError()
    yield "after yield"

@main def main =
  // global exception handler will print OOME to stdout from here but execution will continue
  // because it happens on another thread, not the main thread
  val fut = testFatals() 
  println(fut)
  Await.result(fut, Duration.Inf) // this will hang, this Future will NEVER be resolved