Implicit by-name ClassTag causes an IndexOutOfBoundsException

[nicolasstucki]

minimized code

class Foo {
  inline def foo[T](implicit ct: =>scala.reflect.ClassTag[T]): Unit = Unit
  foo[Int]
  foo[String]
}

Stack trace

java.lang.IndexOutOfBoundsException: 0 while compiling Foo.scala
Exception in thread "main" java.lang.IndexOutOfBoundsException: 0
	at scala.collection.LinearSeqOptimized.apply(LinearSeqOptimized.scala:67)
	at scala.collection.LinearSeqOptimized.apply$(LinearSeqOptimized.scala:65)
	at scala.collection.immutable.List.apply(List.scala:89)
	at dotty.tools.dotc.typer.ErrorReporting$Errors.translate$1(ErrorReporting.scala:156)
	at dotty.tools.dotc.typer.ErrorReporting$Errors.userDefinedErrorString$$anonfun$1(ErrorReporting.scala:158)
	at scala.util.matching.Regex.$anonfun$replaceSomeIn$1$adapted(Regex.scala:535)
	at scala.collection.Iterator.foreach(Iterator.scala:941)
	at scala.collection.Iterator.foreach$(Iterator.scala:941)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1429)
	at scala.util.matching.Regex.replaceSomeIn(Regex.scala:535)
	at dotty.tools.dotc.typer.ErrorReporting$Errors.userDefinedErrorString(ErrorReporting.scala:158)
	at dotty.tools.dotc.typer.Implicits.$anonfun$1(Implicits.scala:1170)
	at scala.Option.map(Option.scala:163)
	at dotty.tools.dotc.typer.Implicits.missingArgMsg(Implicits.scala:1170)
	at dotty.tools.dotc.typer.Typer.missingArgMsg(Typer.scala:84)
	at dotty.tools.dotc.typer.Typer.issueErrors$1$$anonfun$1$$anonfun$1(Typer.scala:2872)
	at dotty.tools.dotc.reporting.diagnostic.MessageContainer.contained(MessageContainer.scala:59)
	at dotty.tools.dotc.reporting.diagnostic.MessageContainer.message(MessageContainer.scala:42)
	at dotty.tools.dotc.reporting.diagnostic.MessageContainer.isNonSensical(MessageContainer.scala:71)
	at dotty.tools.dotc.reporting.HideNonSensicalMessages.isHidden(HideNonSensicalMessages.scala:17)
	at dotty.tools.dotc.reporting.AbstractReporter.isHidden(AbstractReporter.scala:8)
	at dotty.tools.dotc.reporting.Reporter.report(Reporter.scala:256)
	at dotty.tools.dotc.reporting.Reporting.error(Reporter.scala:136)
	at dotty.tools.dotc.core.Contexts$Context.error(Contexts.scala:71)
	at dotty.tools.dotc.typer.Typer.issueErrors$2$$anonfun$2(Typer.scala:2871)
	at dotty.runtime.function.JProcedure3.apply(JProcedure3.java:15)
	at dotty.runtime.function.JProcedure3.apply(JProcedure3.java:10)
	at scala.runtime.Tuple3Zipped$.$anonfun$foreach$1(Tuple3Zipped.scala:124)
	at scala.collection.immutable.List.foreach(List.scala:392)
	at scala.runtime.Tuple3Zipped$.foreach$extension(Tuple3Zipped.scala:122)
	at dotty.tools.dotc.typer.Typer.issueErrors$3(Typer.scala:2875)
	at dotty.tools.dotc.typer.Typer.addImplicitArgs$4(Typer.scala:2900)
	at dotty.tools.dotc.typer.Typer.adaptNoArgsImplicitMethod$2(Typer.scala:2909)
	at dotty.tools.dotc.typer.Typer.adaptNoArgs$1(Typer.scala:3076)
	at dotty.tools.dotc.typer.Typer.adapt1(Typer.scala:3306)
	at dotty.tools.dotc.typer.Typer.adapt(Typer.scala:2720)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2420)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2432)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2475)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2497)
	at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:1671)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2318)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2381)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2420)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2432)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2451)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2497)
	at dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:1795)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2358)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2382)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2420)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2432)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2510)
	at dotty.tools.dotc.typer.FrontEnd.typeCheck$$anonfun$1(FrontEnd.scala:75)
	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
	at dotty.tools.dotc.typer.FrontEnd.monitor(FrontEnd.scala:41)
	at dotty.tools.dotc.typer.FrontEnd.typeCheck(FrontEnd.scala:79)
	at dotty.tools.dotc.typer.FrontEnd.runOn$$anonfun$3(FrontEnd.scala:109)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:392)
	at dotty.tools.dotc.typer.FrontEnd.runOn(FrontEnd.scala:109)
	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:158)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.IndexedSeqOptimized.foreach(IndexedSeqOptimized.scala:36)
	at scala.collection.IndexedSeqOptimized.foreach$(IndexedSeqOptimized.scala:33)
	at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:198)
	at dotty.tools.dotc.Run.runPhases$5(Run.scala:170)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:178)
	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:102)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:185)
	at dotty.tools.dotc.Run.compileSources(Run.scala:120)
	at dotty.tools.dotc.Run.compile(Run.scala:104)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:34)
	at dotty.tools.dotc.Driver.process(Driver.scala:172)
	at dotty.tools.dotc.Driver.process(Driver.scala:141)
	at dotty.tools.dotc.Driver.process(Driver.scala:153)
	at dotty.tools.dotc.Driver.main(Driver.scala:180)
	at dotty.tools.dotc.Main.main(Main.scala)