Following code causes compiler to crash with: `NoSuchElementException: head of empty list @ core.SymDenotations$SymDenotation.recurWithParamss$1(SymDenotations.scala:312)`

[GavinRay97]

Compiler version

3.0.0

Minimized code

https://scastie.scala-lang.org/L6jYE1KFSYqlUA5S8UPfwg

// libraryDependencies += "com.github.pathikrit" % "better-files_2.13" % "3.9.1"
case class FilenameWithPath(filename: String, path: java.nio.file.Path)
def extractFile(it: FilenameWithPath): java.io.File =
  val file: better.files.File = better.files.File(it.path).renameTo(it.filename)
  file.unzipTo(file.parent / file.nameWithoutExtension)

It's the file.unzipTo line -- that code is here if it matters:

• unzipTo
  • https://github.com/pathikrit/better-files/blob/81a3da05c58b9ab0cabe34235c6d7d88bcd16dca/core/src/main/scala/better/files/File.scala#L1178-L1195
• nameWithoutExtension
  • https://github.com/pathikrit/better-files/blob/81a3da05c58b9ab0cabe34235c6d7d88bcd16dca/core/src/main/scala/better/files/File.scala#L61-L92

Output (click arrow to expand)

java.util.NoSuchElementException: head of empty list
	at scala.collection.immutable.Nil$.head(List.scala:662)
	at scala.collection.immutable.Nil$.head(List.scala:661)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.recurWithParamss$1(SymDenotations.scala:312)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.recurWithParamss$1(SymDenotations.scala:312)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.paramSymss(SymDenotations.scala:329)
	at dotty.tools.dotc.typer.Typer.paramSymWithMethodTree$3(Typer.scala:3342)
	at dotty.tools.dotc.typer.Typer.issueErrors$1$$anonfun$1$$anonfun$1(Typer.scala:3354)
	at dotty.tools.dotc.reporting.NoExplanation.msg(Message.scala:133)
	at dotty.tools.dotc.reporting.Message.message(Message.scala:88)
	at dotty.tools.dotc.reporting.Message.isNonSensical(Message.scala:100)
	at dotty.tools.dotc.reporting.HideNonSensicalMessages.isHidden(HideNonSensicalMessages.scala:16)
	at dotty.tools.dotc.reporting.HideNonSensicalMessages.isHidden$(HideNonSensicalMessages.scala:10)
	at dotty.tools.dotc.reporting.AbstractReporter.isHidden(AbstractReporter.scala:8)
	at dotty.tools.dotc.reporting.Reporter.report(Reporter.scala:148)
	at dotty.tools.dotc.report$.error(report.scala:71)
	at dotty.tools.dotc.typer.Typer.issueErrors$2$$anonfun$2(Typer.scala:3356)
	at scala.runtime.function.JProcedure3.apply(JProcedure3.java:15)
	at scala.runtime.function.JProcedure3.apply(JProcedure3.java:10)
	at scala.collection.LazyZip3.foreach(LazyZipOps.scala:248)
	at dotty.tools.dotc.typer.Typer.issueErrors$3(Typer.scala:3358)
	at dotty.tools.dotc.typer.Typer.addImplicitArgs$2$$anonfun$2(Typer.scala:3382)
	at dotty.tools.dotc.typer.Typer.tryEither(Typer.scala:2954)
	at dotty.tools.dotc.typer.Typer.addImplicitArgs$3(Typer.scala:3383)
	at dotty.tools.dotc.typer.Typer.adaptNoArgsImplicitMethod$2(Typer.scala:3401)
	at dotty.tools.dotc.typer.Typer.adaptNoArgs$1(Typer.scala:3598)
	at dotty.tools.dotc.typer.Typer.adapt1(Typer.scala:3811)
	at dotty.tools.dotc.typer.Typer.adapt(Typer.scala:3163)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2823)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2827)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2943)
	at dotty.tools.dotc.typer.Typer.typedBlock(Typer.scala:1029)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2703)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2758)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2823)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2827)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2943)
	at dotty.tools.dotc.typer.Typer.$anonfun$34(Typer.scala:2168)
	at dotty.tools.dotc.typer.PrepareInlineable$.dropInlineIfError(PrepareInlineable.scala:225)
	at dotty.tools.dotc.typer.Typer.typedDefDef(Typer.scala:2168)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2672)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2757)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2823)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2827)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2849)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2899)
	at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:2354)
	at dotty.tools.dotc.typer.Typer.typedTypeOrClassDef$2(Typer.scala:2683)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2687)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2757)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2823)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2827)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2849)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2899)
	at dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:2477)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2728)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2758)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2823)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2827)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2943)
	at dotty.tools.dotc.typer.FrontEnd.liftedTree1$1(FrontEnd.scala:79)
	at dotty.tools.dotc.typer.FrontEnd.typeCheck$$anonfun$1(FrontEnd.scala:84)
	at dotty.tools.dotc.typer.FrontEnd.monitor(FrontEnd.scala:43)
	at dotty.tools.dotc.typer.FrontEnd.typeCheck(FrontEnd.scala:85)
	at dotty.tools.dotc.typer.FrontEnd.runOn$$anonfun$3(FrontEnd.scala:120)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.typer.FrontEnd.runOn(FrontEnd.scala:120)
	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:205)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
	at dotty.tools.dotc.Run.runPhases$5(Run.scala:216)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:224)
	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:231)
	at dotty.tools.dotc.Run.compileSources(Run.scala:166)
	at dotty.tools.dotc.Run.compile(Run.scala:150)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:39)
	at dotty.tools.xsbt.CompilerBridgeDriver.run(CompilerBridgeDriver.java:88)
	at dotty.tools.xsbt.CompilerBridge.run(CompilerBridge.java:22)
	at sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:91)
	at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$7(MixedAnalyzingCompiler.scala:192)
	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
	at sbt.internal.inc.MixedAnalyzingCompiler.timed(MixedAnalyzingCompiler.scala:247)
	at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4(MixedAnalyzingCompiler.scala:182)
	at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4$adapted(MixedAnalyzingCompiler.scala:163)
	at sbt.internal.inc.JarUtils$.withPreviousJar(JarUtils.scala:239)
	at sbt.internal.inc.MixedAnalyzingCompiler.compileScala$1(MixedAnalyzingCompiler.scala:163)
	at sbt.internal.inc.MixedAnalyzingCompiler.compile(MixedAnalyzingCompiler.scala:210)
	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1(IncrementalCompilerImpl.scala:528)
	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1$adapted(IncrementalCompilerImpl.scala:528)
	at sbt.internal.inc.Incremental$.$anonfun$apply$5(Incremental.scala:175)
	at sbt.internal.inc.Incremental$.$anonfun$apply$5$adapted(Incremental.scala:173)
	at sbt.internal.inc.Incremental$$anon$2.run(Incremental.scala:459)
	at sbt.internal.inc.IncrementalCommon$CycleState.next(IncrementalCommon.scala:116)
	at sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:56)
	at sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:52)
	at sbt.internal.inc.IncrementalCommon.cycle(IncrementalCommon.scala:263)
	at sbt.internal.inc.Incremental$.$anonfun$incrementalCompile$8(Incremental.scala:414)
	at sbt.internal.inc.Incremental$.withClassfileManager(Incremental.scala:501)
	at sbt.internal.inc.Incremental$.incrementalCompile(Incremental.scala:401)
	at sbt.internal.inc.Incremental$.apply(Incremental.scala:167)
	at sbt.internal.inc.IncrementalCompilerImpl.compileInternal(IncrementalCompilerImpl.scala:528)
	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileIncrementally$1(IncrementalCompilerImpl.scala:482)
	at sbt.internal.inc.IncrementalCompilerImpl.handleCompilationError(IncrementalCompilerImpl.scala:332)
	at sbt.internal.inc.IncrementalCompilerImpl.compileIncrementally(IncrementalCompilerImpl.scala:420)
	at sbt.internal.inc.IncrementalCompilerImpl.compile(IncrementalCompilerImpl.scala:137)
	at sbt.Defaults$.compileIncrementalTaskImpl(Defaults.scala:2357)
	at sbt.Defaults$.$anonfun$compileIncrementalTask$2(Defaults.scala:2314)
	at sbt.internal.io.Retry$.apply(Retry.scala:46)
	at sbt.internal.io.Retry$.apply(Retry.scala:28)
	at sbt.internal.io.Retry$.apply(Retry.scala:23)
	at sbt.internal.server.BspCompileTask$.compute(BspCompileTask.scala:31)
	at sbt.Defaults$.$anonfun$compileIncrementalTask$1(Defaults.scala:2310)
	at scala.Function1.$anonfun$compose$1(Function1.scala:49)
	at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
	at sbt.std.Transform$$anon$4.work(Transform.scala:68)
	at sbt.Execute.$anonfun$submit$2(Execute.scala:282)
	at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:23)
	at sbt.Execute.work(Execute.scala:291)
	at sbt.Execute.$anonfun$submit$1(Execute.scala:282)
	at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:265)
	at sbt.CompletionService$$anon$2.call(CompletionService.scala:64)

[griggt]

Minimized to:

foo.scala

// Compile with Scala 2.13
trait Bar
class Foo {
  def foo(out: Foo)(implicit bar: Bar): out.type = out
}

boom.scala

// no implicit of type Bar in scope
def boom(foo: Foo) = foo.foo(foo)

$ scalac -version && dotc -version
Scala compiler version 2.13.6 -- Copyright 2002-2021, LAMP/EPFL and Lightbend, Inc.
Scala compiler version 3.0.3-RC1-bin-SNAPSHOT-git-814fca6 -- Copyright 2002-2021, LAMP/EPFL

$ scalac foo.scala 
$ dotc boom.scala
exception occurred while typechecking boom.scala
exception occurred while compiling boom.scala
java.util.NoSuchElementException: head of empty list while compiling boom.scala
Exception in thread "main" java.util.NoSuchElementException: head of empty list
	at scala.collection.immutable.Nil$.head(List.scala:662)
	at scala.collection.immutable.Nil$.head(List.scala:661)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.recurWithParamss$1(SymDenotations.scala:312)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.recurWithParamss$1(SymDenotations.scala:312)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.paramSymss(SymDenotations.scala:329)
	at dotty.tools.dotc.typer.Typer.paramSymWithMethodTree$3(Typer.scala:3344)
	at dotty.tools.dotc.typer.Typer.issueErrors$1$$anonfun$1$$anonfun$1(Typer.scala:3356)
	at dotty.tools.dotc.reporting.NoExplanation.msg(Message.scala:132)
	at dotty.tools.dotc.reporting.Message.message(Message.scala:87)
	at dotty.tools.dotc.reporting.Message.isNonSensical(Message.scala:99)
	at dotty.tools.dotc.reporting.HideNonSensicalMessages.isHidden(HideNonSensicalMessages.scala:16)
	at dotty.tools.dotc.reporting.HideNonSensicalMessages.isHidden$(HideNonSensicalMessages.scala:10)
	at dotty.tools.dotc.reporting.AbstractReporter.isHidden(AbstractReporter.scala:8)
	at dotty.tools.dotc.reporting.Reporter.report(Reporter.scala:148)
	at dotty.tools.dotc.report$.error(report.scala:71)
	at dotty.tools.dotc.typer.Typer.issueErrors$2$$anonfun$2(Typer.scala:3358)
	at scala.runtime.function.JProcedure3.apply(JProcedure3.java:15)
	at scala.runtime.function.JProcedure3.apply(JProcedure3.java:10)
	at scala.collection.LazyZip3.foreach(LazyZipOps.scala:248)
	at dotty.tools.dotc.typer.Typer.issueErrors$3(Typer.scala:3360)
	at dotty.tools.dotc.typer.Typer.addImplicitArgs$3(Typer.scala:3386)
	at dotty.tools.dotc.typer.Typer.adaptNoArgsImplicitMethod$2(Typer.scala:3403)
	at dotty.tools.dotc.typer.Typer.adaptNoArgs$1(Typer.scala:3600)
	at dotty.tools.dotc.typer.Typer.adapt1(Typer.scala:3813)
	at dotty.tools.dotc.typer.Typer.adapt(Typer.scala:3165)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2824)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2828)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2944)
	at dotty.tools.dotc.typer.Namer.typedAheadExpr$$anonfun$1(Namer.scala:1424)
	at dotty.tools.dotc.typer.Namer.typedAhead(Namer.scala:1414)
	at dotty.tools.dotc.typer.Namer.typedAheadExpr(Namer.scala:1424)
	at dotty.tools.dotc.typer.Namer.typedAheadRhs$1$$anonfun$1(Namer.scala:1676)
	at dotty.tools.dotc.typer.PrepareInlineable$.dropInlineIfError(PrepareInlineable.scala:225)
	at dotty.tools.dotc.typer.Namer.typedAheadRhs$2(Namer.scala:1676)
	at dotty.tools.dotc.typer.Namer.rhsType$1(Namer.scala:1684)
	at dotty.tools.dotc.typer.Namer.cookedRhsType$1(Namer.scala:1711)
	at dotty.tools.dotc.typer.Namer.lhsType$1(Namer.scala:1712)
	at dotty.tools.dotc.typer.Namer.inferredResultType(Namer.scala:1723)
	at dotty.tools.dotc.typer.Namer.inferredType$1(Namer.scala:1463)
	at dotty.tools.dotc.typer.Namer.valOrDefDefSig(Namer.scala:1470)
	at dotty.tools.dotc.typer.Namer.defDefSig(Namer.scala:1554)
	at dotty.tools.dotc.typer.Namer$Completer.typeSig(Namer.scala:755)
	at dotty.tools.dotc.typer.Namer$Completer.completeInCreationContext(Namer.scala:887)
	at dotty.tools.dotc.typer.Namer$Completer.complete(Namer.scala:779)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.completeFrom(SymDenotations.scala:167)
	at dotty.tools.dotc.core.Denotations$Denotation.completeInfo$1(Denotations.scala:188)
	at dotty.tools.dotc.core.Denotations$Denotation.info(Denotations.scala:190)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.ensureCompleted(SymDenotations.scala:369)
	at dotty.tools.dotc.typer.Typer.retrieveSym(Typer.scala:2638)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2663)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2758)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2824)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2828)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2850)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2900)
	at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:2355)
	at dotty.tools.dotc.typer.Typer.typedTypeOrClassDef$2(Typer.scala:2684)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2688)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2758)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2824)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2828)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2850)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2900)
	at dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:2478)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2729)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2759)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2824)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2828)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2944)
	at dotty.tools.dotc.typer.FrontEnd.liftedTree1$1(FrontEnd.scala:79)
	at dotty.tools.dotc.typer.FrontEnd.typeCheck$$anonfun$1(FrontEnd.scala:84)
	at dotty.tools.dotc.typer.FrontEnd.monitor(FrontEnd.scala:43)
	at dotty.tools.dotc.typer.FrontEnd.typeCheck(FrontEnd.scala:85)
	at dotty.tools.dotc.typer.FrontEnd.runOn$$anonfun$3(FrontEnd.scala:120)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.typer.FrontEnd.runOn(FrontEnd.scala:120)
	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:205)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
	at dotty.tools.dotc.Run.runPhases$5(Run.scala:216)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:224)
	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:231)
	at dotty.tools.dotc.Run.compileSources(Run.scala:166)
	at dotty.tools.dotc.Run.compile(Run.scala:150)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:39)
	at dotty.tools.dotc.Driver.process(Driver.scala:199)
	at dotty.tools.dotc.Driver.process(Driver.scala:167)
	at dotty.tools.dotc.Driver.process(Driver.scala:179)
	at dotty.tools.dotc.Driver.main(Driver.scala:209)
	at dotty.tools.dotc.Main.main(Main.scala)