Crash on missing parens around named tuple in custom extractor

[TomasMikula]

Compiler version

3.7.1

Minimized code

import NamedTuple.AnyNamedTuple

sealed trait Z
sealed trait S[n]

type TupleList[+A, N] <: AnyNamedTuple =
  N match
    case Z => NamedTuple.Empty
    case S[n] => (head: A, tail: TupleList[A, n])

sealed trait Vect[+A, N]:
  def ::[A1 >: A](a: A1): Vect[A1, S[N]] =
    Vect.Cons(a, this)

  def toTupleList: TupleList[A, N]

object Vect:
  case object Empty extends Vect[Nothing, Z]:
    override def toTupleList: TupleList[Nothing, Z] = NamedTuple.Empty

  case class Cons[A, N](head: A, tail: Vect[A, N]) extends Vect[A, S[N]]:
    override def toTupleList: TupleList[A, S[N]] = (head, tail.toTupleList)

object Foo:
  def unapply[A, N](as: Vect[A, N]): Some[TupleList[A, N]] =
    Some(as.toTupleList)

@main
def test: Unit =
  (1 :: 2 :: 3 :: Vect.Empty) match
    // missing parens around named tuple inside Foo causes compiler crash
    case Foo(head = h, tail = t) =>
      ()

Output (click arrow to expand)

% scalac test.scala

  unhandled exception while running MegaPhase{protectedAccessors, extmethods, uncacheGivenAliases, checkStatic, elimByName, hoistSuperArgs, forwardDepChecks, specializeApplyMethods, tryCatchPatterns, patternMatcher} on test.scala

  An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/scala/scala3/issues/new/choose
  For non-enriched exceptions, compile with -Xno-enrich-error-messages.


     while compiling: test.scala
        during phase: MegaPhase{protectedAccessors, extmethods, uncacheGivenAliases, checkStatic, elimByName, hoistSuperArgs, forwardDepChecks, specializeApplyMethods, tryCatchPatterns, patternMatcher}
                mode: Mode(ImplicitsEnabled)
     library version: version 2.13.16
    compiler version: version 3.7.1
            settings: 

Exception in thread "main" scala.MatchError: List() (of class scala.collection.immutable.Nil$)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.matchArgsPatternPlan$1(PatternMatcher.scala:270)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.matchArgsComponentsPlan$1(PatternMatcher.scala:265)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.matchArgsPlan$1(PatternMatcher.scala:276)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.$anonfun$13(PatternMatcher.scala:403)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.letAbstract(PatternMatcher.scala:117)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.unapplyPlan$1$$anonfun$1(PatternMatcher.scala:388)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.letAbstract(PatternMatcher.scala:117)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.unapplyPlan$1(PatternMatcher.scala:360)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.patternPlan(PatternMatcher.scala:444)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.caseDefPlan(PatternMatcher.scala:480)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan$$anonfun$1$$anonfun$1(PatternMatcher.scala:487)
	at scala.collection.immutable.List.foldRight(List.scala:353)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan$$anonfun$1(PatternMatcher.scala:486)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.letAbstract(PatternMatcher.scala:117)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan(PatternMatcher.scala:484)
	at dotty.tools.dotc.transform.PatternMatcher$Translator.translateMatch(PatternMatcher.scala:1072)
	at dotty.tools.dotc.transform.PatternMatcher.transformMatch(PatternMatcher.scala:47)
	at dotty.tools.dotc.transform.MegaPhase.goMatch(MegaPhase.scala:816)
	at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:383)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:454)
	at dotty.tools.dotc.transform.MegaPhase.mapDefDef$1(MegaPhase.scala:265)
	at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:268)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:452)
	at dotty.tools.dotc.transform.MegaPhase.loop$1(MegaPhase.scala:465)
	at dotty.tools.dotc.transform.MegaPhase.transformStats(MegaPhase.scala:465)
	at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:376)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:454)
	at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:272)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:452)
	at dotty.tools.dotc.transform.MegaPhase.loop$1(MegaPhase.scala:465)
	at dotty.tools.dotc.transform.MegaPhase.transformStats(MegaPhase.scala:465)
	at dotty.tools.dotc.transform.MegaPhase.mapPackage$1(MegaPhase.scala:396)
	at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:399)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:454)
	at dotty.tools.dotc.transform.MegaPhase.transformUnit(MegaPhase.scala:481)
	at dotty.tools.dotc.transform.MegaPhase.run(MegaPhase.scala:493)
	at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:383)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:334)
	at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:376)
	at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:368)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1324)
	at dotty.tools.dotc.Run.runPhases$1(Run.scala:361)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1$$anonfun$2(Run.scala:408)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1$$anonfun$adapted$1(Run.scala:408)
	at scala.Function0.apply$mcV$sp(Function0.scala:42)
	at dotty.tools.dotc.Run.showProgress(Run.scala:470)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:408)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:420)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:69)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:420)
	at dotty.tools.dotc.Run.compileSources(Run.scala:307)
	at dotty.tools.dotc.Run.compile(Run.scala:292)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:37)
	at dotty.tools.dotc.Driver.process(Driver.scala:201)
	at dotty.tools.dotc.Driver.process(Driver.scala:169)
	at dotty.tools.dotc.Driver.process(Driver.scala:181)
	at dotty.tools.dotc.Driver.main(Driver.scala:211)
	at dotty.tools.MainGenericCompiler$.run$1(MainGenericCompiler.scala:162)
	at dotty.tools.MainGenericCompiler$.main(MainGenericCompiler.scala:186)
	at dotty.tools.MainGenericCompiler.main(MainGenericCompiler.scala)

Expectation

I'd expect the compiler to report an error about the pattern being wrong.