manually-with-scope with child parallelization launched co-routines

Code

package com.glassthought.sandbox

import gt.sandbox.util.output.Out
import kotlinx.coroutines.*
import kotlin.coroutines.coroutineContext
import kotlin.system.exitProcess
import kotlin.time.Duration.Companion.seconds

private val out = Out.standard()

fun main(): Unit = runBlocking {
  out.info("START - ON MAIN")

  try {
    mainImpl(out)
  } catch (e: Exception) {
    out.error("back at MAIN got an exception! of type=[${e::class.simpleName}] with msg=[${e.message}] cause=[${e.cause}]. Exiting with error code 1")

    exitProcess(1)
  }

  out.info("DONE - WITHOUT errors on MAIN")
}

private suspend fun mainImpl(out: Out) {
  coroutineScope {
    foo("msg-1")
  }
}

private suspend fun foo(msg: String) {
  out.actionWithMsg("fooImpl", { fooImpl(msg) })
}

private suspend fun fooImpl(msg: String) {
  val job = Job()
  val scope = CoroutineScope(coroutineContext + job)

  scope.launch {
    out.delayNamed(3.seconds, "delayed([${msg}])")
  }
  scope.launch {
    out.delayNamed(2.seconds, "delayed([${msg}])")
  }
  scope.launch {
    out.delayNamed(1.seconds, "delayed([${msg}])")
  }

  out.actionWithMsg("job.complete()", { job.complete() })
  out.actionWithMsg("job.join()", { job.join() })
}

Command to reproduce:

gt.sandbox.checkout.commit 800315e25e0cc39077c2 \
&& cd "${GT_SANDBOX_REPO}" \
&& cmd.run.announce "./gradlew run --quiet"

Recorded output of command:

Picked up JAVA_TOOL_OPTIONS: -Dkotlinx.coroutines.debug
Picked up JAVA_TOOL_OPTIONS: -Dkotlinx.coroutines.debug
[INFO][elapsed:   37ms][🥇][①][coroutname:@coroutine#1][tname:main/tid:1] START - ON MAIN
[INFO][elapsed:   52ms][🥇][①][coroutname:@coroutine#1][tname:main/tid:1] [>] Starting action=[fooImpl] 
[INFO][elapsed:   54ms][🥇][①][coroutname:@coroutine#1][tname:main/tid:1]    [>] Starting action=[job.complete()] 
[INFO][elapsed:   55ms][🥇][①][coroutname:@coroutine#1][tname:main/tid:1]    [<] Finished action=[job.complete()].
[INFO][elapsed:   55ms][🥇][①][coroutname:@coroutine#1][tname:main/tid:1]    [>] Starting action=[job.join()] 
[INFO][elapsed:   59ms][🥇][⓶][coroutname:@coroutine#2][tname:main/tid:1] Delaying for 3s what_for=[delayed([msg-1])]
[INFO][elapsed:   60ms][🥇][⓷][coroutname:@coroutine#3][tname:main/tid:1] Delaying for 2s what_for=[delayed([msg-1])]
[INFO][elapsed:   61ms][🥇][⓸][coroutname:@coroutine#4][tname:main/tid:1] Delaying for 1s what_for=[delayed([msg-1])]
[INFO][elapsed: 1062ms][🥇][⓸][coroutname:@coroutine#4][tname:main/tid:1] Done delaying for 1s what_for=[delayed([msg-1])]
[INFO][elapsed: 2061ms][🥇][⓷][coroutname:@coroutine#3][tname:main/tid:1] Done delaying for 2s what_for=[delayed([msg-1])]
[INFO][elapsed: 3060ms][🥇][⓶][coroutname:@coroutine#2][tname:main/tid:1] Done delaying for 3s what_for=[delayed([msg-1])]
[INFO][elapsed: 3061ms][🥇][①][coroutname:@coroutine#1][tname:main/tid:1]    [<] Finished action=[job.join()].
[INFO][elapsed: 3061ms][🥇][①][coroutname:@coroutine#1][tname:main/tid:1] [<] Finished action=[fooImpl].
[INFO][elapsed: 3061ms][🥇][①][coroutname:@coroutine#1][tname:main/tid:1] DONE - WITHOUT errors on MAIN