compiler crashes with call of function with second given parameter with default value

[rssh]

minimized code

package X
  
import scala.concurrent._
import scala.concurrent.duration._

import scala.concurrent.ExecutionContext.Implicits._

class Test1 {

  def spawn[T](f: => T)(given ec:ExecutionContext,  naming: Int = 3): Future[T] = ???

  def await[T](f:Future[T], atMost: Duration = Duration.Inf)(given ec: ExecutionContext):T = ???

  def test(): Unit = {
    val promiseToWait = Promise[Int]()
    val future1 = spawn{
       val x = await(promiseToWait.future)
       x+1
    }
  }


}

Stack trace

[error]            
[error] java.util.NoSuchElementException: val x
[error] 	at scala.collection.mutable.AnyRefMap$ExceptionDefault.apply(AnyRefMap.scala:495)
[error] 	at scala.collection.mutable.AnyRefMap$ExceptionDefault.apply(AnyRefMap.scala:494)
[error] 	at scala.collection.mutable.AnyRefMap.apply(AnyRefMap.scala:205)
[error] 	at dotty.tools.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder$locals$.load(BCodeSkelBuilder.scala:396)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:393)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoadArguments$$anonfun$1(BCodeBodyBuilder.scala:1052)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:305)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoadArguments(BCodeBodyBuilder.scala:1052)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:335)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:409)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoadArguments$$anonfun$1(BCodeBodyBuilder.scala:1052)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:305)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoadArguments(BCodeBodyBuilder.scala:1052)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genNormalMethodCall$1(BCodeBodyBuilder.scala:785)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genApply(BCodeBodyBuilder.scala:814)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:339)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:409)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:286)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genStat(BCodeBodyBuilder.scala:83)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genBlock$$anonfun$1(BCodeBodyBuilder.scala:918)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:305)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genBlock(BCodeBodyBuilder.scala:918)
[error] 	at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:410)
[error] 	at dotty.tools.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.emitNormalMethodBody$1(BCodeSkelBuilder.scala:597)
[error] 	at dotty.tools.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.genDefDef(BCodeSkelBuilder.scala:630)
[error] 	at dotty.tools.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.gen(BCodeSkelBuilder.scala:501)
[error] 	at dotty.tools.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.gen$$anonfun$1(BCodeSkelBuilder.scala:503)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:305)
[error] 	at dotty.tools.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.gen(BCodeSkelBuilder.scala:503)
[error] 	at dotty.tools.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.genPlainClass(BCodeSkelBuilder.scala:109)
[error] 	at dotty.tools.backend.jvm.GenBCodePipeline$Worker1.visit(GenBCode.scala:217)
[error] 	at dotty.tools.backend.jvm.GenBCodePipeline$Worker1.run(GenBCode.scala:184)
[error] 	at dotty.tools.backend.jvm.GenBCodePipeline.buildAndSendToDisk(GenBCode.scala:514)
[error] 	at dotty.tools.backend.jvm.GenBCodePipeline.run(GenBCode.scala:480)
[error] 	at dotty.tools.backend.jvm.GenBCode.run(GenBCode.scala:51)
[error] 	at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:315)
[error] 	at scala.collection.immutable.List.map(List.scala:219)
[error] 	at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:316)
[error] 	at dotty.tools.backend.jvm.GenBCode.runOn(GenBCode.scala:55)
[error] 	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:162)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
[error] 	at dotty.tools.dotc.Run.runPhases$5(Run.scala:172)
[error] 	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:180)
[error] 	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] 	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
[error] 	at dotty.tools.dotc.Run.compileUnits(Run.scala:187)
[error] 	at dotty.tools.dotc.Run.compileSources(Run.scala:124)
[error] 	at dotty.tools.dotc.Run.compile(Run.scala:107)
[error] 	at dotty.tools.dotc.Driver.doCompile(Driver.scala:36)
[error] 	at dotty.tools.dotc.Driver.process(Driver.scala:189)
[error] 	at dotty.tools.dotc.Main.process(Main.scala)
[error] 	at xsbt.CachedCompilerImpl.run(CachedCompilerImpl.java:69)
[error] 	at xsbt.CompilerInterface.run(CompilerInterface.java:41)
[error] 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[error] 	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[error] 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[error] 	at java.lang.reflect.Method.invoke(Method.java:498)
[error] 	at sbt.internal.inc.AnalyzingCompiler.call(AnalyzingCompiler.scala:248)
[error] 	at sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:122)
[error] 	at sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:95)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4(MixedAnalyzingCompiler.scala:91)
[error] 	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.timed(MixedAnalyzingCompiler.scala:186)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$3(MixedAnalyzingCompiler.scala:82)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$3$adapted(MixedAnalyzingCompiler.scala:77)
[error] 	at sbt.internal.inc.JarUtils$.withPreviousJar(JarUtils.scala:215)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.compileScala$1(MixedAnalyzingCompiler.scala:77)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.compile(MixedAnalyzingCompiler.scala:146)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1(IncrementalCompilerImpl.scala:343)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1$adapted(IncrementalCompilerImpl.scala:343)
[error] 	at sbt.internal.inc.Incremental$.doCompile(Incremental.scala:120)
[error] 	at sbt.internal.inc.Incremental$.$anonfun$compile$4(Incremental.scala:100)
[error] 	at sbt.internal.inc.IncrementalCommon.recompileClasses(IncrementalCommon.scala:180)
[error] 	at sbt.internal.inc.IncrementalCommon.cycle(IncrementalCommon.scala:98)
[error] 	at sbt.internal.inc.Incremental$.$anonfun$compile$3(Incremental.scala:102)
[error] 	at sbt.internal.inc.Incremental$.manageClassfiles(Incremental.scala:155)
[error] 	at sbt.internal.inc.Incremental$.compile(Incremental.scala:92)
[error] 	at sbt.internal.inc.IncrementalCompile$.apply(Compile.scala:75)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.compileInternal(IncrementalCompilerImpl.scala:348)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileIncrementally$1(IncrementalCompilerImpl.scala:301)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.handleCompilationError(IncrementalCompilerImpl.scala:168)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.compileIncrementally(IncrementalCompilerImpl.scala:248)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.compile(IncrementalCompilerImpl.scala:74)
[error] 	at sbt.Defaults$.compileIncrementalTaskImpl(Defaults.scala:1761)
[error] 	at sbt.Defaults$.$anonfun$compileIncrementalTask$1(Defaults.scala:1734)
[error] 	at scala.Function1.$anonfun$compose$1(Function1.scala:49)
[error] 	at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
[error] 	at sbt.std.Transform$$anon$4.work(Transform.scala:67)
[error] 	at sbt.Execute.$anonfun$submit$2(Execute.scala:281)
[error] 	at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19)
[error] 	at sbt.Execute.work(Execute.scala:290)
[error] 	at sbt.Execute.$anonfun$submit$1(Execute.scala:281)
[error] 	at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178)
[error] 	at sbt.CompletionService$$anon$2.call(CompletionService.scala:37)
[error] 	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[error] 	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[error] 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[error] 	at java.lang.Thread.run(Thread.java:748)
[error] (Compile / compileIncremental) java.util.NoSuchElementException: val x

[nicolasstucki]

Can be minimized to

class Test1 {
  def spawn(f: => Unit)(given naming: Int = 4): Unit = ???
  def test(): Unit = spawn {
    val x: Int = 5
    x
  }
}

the bug appears in lambdaLift where f$1 gets a parameter it should not

result of Foo.scala after MegaPhase{constructors, functionalInterfaces, getClass, liftTry}:
package <empty> {
  @scala.annotation.internal.SourceFile("Foo.scala") class Test1 extends Object
     {
    def <init>(): Unit = 
      {
        super()
        ()
      }
    def spawn(f: Function0, naming: Int): Unit = ???()
    def spawn$default$2(f: Function0): Int = 4
    def test(): Unit = 
      {
        def f$1(): Unit = 
          {
            val x: Int = 5
            {
              x
              ()
            }
          }
        this.spawn(
          {
            def $anonfun(): Unit = f$1()
            closure($anonfun:JFunction0$mcV$sp)
          }
        , 
          this.spawn$default$2(
            {
              def $anonfun(): Unit = f$1()
              closure($anonfun:JFunction0$mcV$sp)
            }
          )
        )
      }
  }
}
result of Foo.scala after MegaPhase{linkScala2Impls, lambdaLift, elimStaticThis}:
package <empty> {
  @scala.annotation.internal.SourceFile("Foo.scala") class Test1 extends Object
     {
    def <init>(): Unit = 
      {
        super()
        ()
      }
    def spawn(f: Function0, naming: Int): Unit = ???()
    def spawn$default$2(f: Function0): Int = 4
    def test(): Unit = 
      {
        this.spawn(
          {
            closure(x | <empty>.this.test$$anonfun$1:JFunction0$mcV$sp)
          }
        , 
          this.spawn$default$2(
            {
              closure(x | <empty>.this.test$$anonfun$2:JFunction0$mcV$sp)
            }
          )
        )
      }
    private final <static> def f$1$1(x$1: Int): Unit = 
      {
        val x: Int = 5
        {
          x$1
          ()
        }
      }
    private final <static> def test$$anonfun$1(x$2: Int): Unit = this.f$1$1(x$2)
    private final <static> def test$$anonfun$2(x$3: Int): Unit = this.f$1$1(x$3)
  }
}