Deadlock in ZIO with `Runtime.default` runtime

TestDefaultRuntime.scala

/*
Dependencies: 
- scala 2.13.1
- zio 1.0.0-RC18-1+44-24f507c2+20200310-2150-SNAPSHOT (local build on master on 2020-03-10)
- with openjdk 11.0.4+11
*/

package some.pkg

import zio.Runtime
import zio.UIO
import zio.ZIO
import zio.ZLayer

class internalRuntime {

  lazy val runtime = Runtime.default
  runtime.unsafeRun(UIO.effectTotal(println("**** case 0: non blocking")))
  unsafeRun(UIO.effectTotal(println("**** case 1: blocking")))

  def blocking[E, A](e: ZIO[Any, E, A]): ZIO[Any, E, A] = {
    ZIO.accessM[_root_.zio.blocking.Blocking](_.get.blocking(e)).provideLayer(ZLayer.succeedMany(runtime.environment))
  }
  def unsafeRun[E, A](e: => ZIO[Any, E, A]): Unit = {
    runtime.unsafeRun(ZIO.accessM[_root_.zio.blocking.Blocking](_.get.blocking(e)))
  }

}

object someRoot { // this is the entry point for my runtime
  lazy val zioRuntime = new internalRuntime()
}

object Elsewhere { // somewhere else, a blocking unsafe run is called

  someRoot.zioRuntime.runtime.unsafeRun(UIO.effectTotal(println("**** case 1000: non blocking")))
  someRoot.zioRuntime.unsafeRun(UIO.effectTotal(println("**** case 2000: blocking")))

  def print()= println("ok")
}

object TestRuntime {
  def main(args: Array[String]): Unit = {
    // in internal, it blocks
    someRoot.zioRuntime.runtime.unsafeRun(UIO.effectTotal(println("**** case 100: non blocking")))
    someRoot.zioRuntime.unsafeRun(UIO.effectTotal(println("**** case 200: blocking")))

    // it blocks here, when calling the blocking variant
    Elsewhere.print()
    println("done")

/* console output:
**** case 0: non blocking
**** case 1: blocking
**** case 100: non blocking
**** case 200: blocking
**** case 1000: non blocking
 -- blocks here --
"main@1" prio=5 tid=0x1 nid=NA waiting
  java.lang.Thread.State: WAITING
	  at java.lang.Object.wait(Object.java:-1)
	  at java.lang.Object.wait(Object.java:328)
	  at zio.internal.OneShot.get(OneShot.scala:79)
	  at zio.Runtime.unsafeRunSync(Runtime.scala:82)
	  at zio.Runtime.unsafeRunSync$(Runtime.scala:77)
	  at zio.Runtime$$anon$2.unsafeRunSync(Runtime.scala:226)
	  at zio.Runtime.unsafeRun(Runtime.scala:57)
	  at zio.Runtime.unsafeRun$(Runtime.scala:56)
	  at zio.Runtime$$anon$2.unsafeRun(Runtime.scala:226)
	  at com.normation.internalRuntime.unsafeRun(ZioCommonsTest.scala:91)
	  at com.normation.Elsewhere$.<clinit>(ZioCommonsTest.scala:103)
	  at com.normation.TestRuntime$.main(ZioCommonsTest.scala:115)
	  at com.normation.TestRuntime.main(ZioCommonsTest.scala:-1)

"zio-default-blocking-1-399534175@1482" daemon prio=5 tid=0xf nid=NA runnable
  java.lang.Thread.State: RUNNABLE
	  at com.normation.Elsewhere$$$Lambda$142.1966250569.apply$mcV$sp(Unknown Source:-1)
	  at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18)
	  at zio.internal.FiberContext.evaluateNow(FiberContext.scala:382)
	  at zio.internal.FiberContext.$anonfun$evaluateLater$1(FiberContext.scala:687)
	  at zio.internal.FiberContext$$Lambda$125.1907431275.run(Unknown Source:-1)
	  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	  at java.lang.Thread.run(Thread.java:834)
* */
  }
}