Exception when running inner quote

[biboudis]

import scala.quoted._

object Test {
  implicit val toolbox: scala.quoted.Toolbox = scala.quoted.Toolbox.make(getClass.getClassLoader)
  val ret: Expr[Int => Int] = '{ (x: Int) => ${ val z = run('{x + 1}); z.toExpr } }
  def main(args: Array[String]): Unit = {
    println(run(ret).apply(10))
  }
}

fails when running with:

Exception in thread "main" java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at dotty.tools.vulpix.ChildJVMMain.runMain(ChildJVMMain.java:40)
	at dotty.tools.vulpix.ChildJVMMain.main(ChildJVMMain.java:47)
Caused by: java.lang.IllegalArgumentException: Could not find proxy for x: Int in List(val x, method $anonfun, method apply, class Generated$Code$From$Quoted, module class <root>), encl = method apply, owners = method apply, class Generated$Code$From$Quoted, package <root>; enclosures = method apply, class Generated$Code$From$Quoted, package <root>
	at dotty.tools.dotc.transform.LambdaLift$Lifter.searchIn$1(LambdaLift.scala:381)
	at dotty.tools.dotc.transform.LambdaLift$Lifter.proxy(LambdaLift.scala:394)
	at dotty.tools.dotc.transform.LambdaLift$Lifter.proxyRef(LambdaLift.scala:412)
	at dotty.tools.dotc.transform.LambdaLift.transformIdent(LambdaLift.scala:526)
	at dotty.tools.dotc.transform.MegaPhase.goIdent(MegaPhase.scala:551)
	at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:225)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:394)
	at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:228)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:394)
	at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:270)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:396)
	at dotty.tools.dotc.transform.MegaPhase.transformTrees$$anonfun$1(MegaPhase.scala:420)
	at scala.collection.immutable.List.mapConserve(List.scala:179)
	at dotty.tools.dotc.transform.MegaPhase.transformTrees(MegaPhase.scala:420)
	at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:271)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:396)
	at dotty.tools.dotc.transform.MegaPhase.mapDefDef$1(MegaPhase.scala:245)
	at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:248)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:394)
	at dotty.tools.dotc.transform.MegaPhase.transformStat$2(MegaPhase.scala:404)
	at dotty.tools.dotc.transform.MegaPhase.$anonfun$1(MegaPhase.scala:409)
	at scala.collection.immutable.List.mapConserve(List.scala:179)
	at dotty.tools.dotc.transform.MegaPhase.transformStats(MegaPhase.scala:409)
	at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:339)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:396)
	at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:251)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:394)