MatchError when using refutable extractor

[griggt]

Minimized from the community build failure of erikerlandson/coulomb reported in #15647

Compiler version

3.2.0-RC2
Works in 3.1.3

Minimized code

class Rational

import scala.quoted.*

object meta:
  object rationalTE:
    def unapply(using Quotes)(tr: quotes.reflect.TypeRepr): Option[Rational] = ???

  def foo(using Quotes)(p: quotes.reflect.TypeRepr): Unit =
    val rationalTE(e) = p

Output (click arrow to expand)

exception occurred while typechecking meta.scala
exception occurred while compiling meta.scala
scala.MatchError: Apply(Select(Ident(rationalTE),unapply),List(Ident(x$1))) (of class dotty.tools.dotc.ast.Trees$Apply) while compiling meta.scala
Exception in thread "main" scala.MatchError: Apply(Select(Ident(rationalTE),unapply),List(Ident(x$1))) (of class dotty.tools.dotc.ast.Trees$Apply)
	at dotty.tools.dotc.typer.Checking.fail$1(Checking.scala:821)
	at dotty.tools.dotc.typer.Checking.recur$1(Checking.scala:860)
	at dotty.tools.dotc.typer.Checking.checkIrrefutable(Checking.scala:874)
	at dotty.tools.dotc.typer.Checking.checkIrrefutable$(Checking.scala:776)
	at dotty.tools.dotc.typer.Typer.checkIrrefutable(Typer.scala:117)
	at dotty.tools.dotc.typer.Typer.typedMatch(Typer.scala:1612)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2873)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2922)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2987)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2991)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3107)
	at dotty.tools.dotc.typer.Namer.typedAheadExpr$$anonfun$1(Namer.scala:1618)
	at dotty.tools.dotc.typer.Namer.typedAhead(Namer.scala:1608)
	at dotty.tools.dotc.typer.Namer.typedAheadExpr(Namer.scala:1618)
	at dotty.tools.dotc.typer.Namer.typedAheadRhs$1$$anonfun$1(Namer.scala:1866)
	at dotty.tools.dotc.typer.PrepareInlineable$.dropInlineIfError(PrepareInlineable.scala:248)
	at dotty.tools.dotc.typer.Namer.typedAheadRhs$1(Namer.scala:1866)
	at dotty.tools.dotc.typer.Namer.rhsType$1(Namer.scala:1874)
	at dotty.tools.dotc.typer.Namer.cookedRhsType$1(Namer.scala:1892)
	at dotty.tools.dotc.typer.Namer.lhsType$1(Namer.scala:1893)
	at dotty.tools.dotc.typer.Namer.inferredResultType(Namer.scala:1904)
	at dotty.tools.dotc.typer.Namer.inferredType$1(Namer.scala:1657)
	at dotty.tools.dotc.typer.Namer.valOrDefDefSig(Namer.scala:1664)
	at dotty.tools.dotc.typer.Namer$Completer.typeSig(Namer.scala:782)
	at dotty.tools.dotc.typer.Namer$Completer.completeInCreationContext(Namer.scala:921)
	at dotty.tools.dotc.typer.Namer$Completer.complete(Namer.scala:809)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.completeFrom(SymDenotations.scala:171)
	at dotty.tools.dotc.core.Denotations$Denotation.completeInfo$1(Denotations.scala:187)
	at dotty.tools.dotc.core.Denotations$Denotation.info(Denotations.scala:189)
	at dotty.tools.dotc.core.SymDenotations$SymDenotation.ensureCompleted(SymDenotations.scala:373)
	at dotty.tools.dotc.typer.Typer.retrieveSym(Typer.scala:2800)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2825)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2921)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2987)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2991)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3013)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3063)
	at dotty.tools.dotc.typer.Typer.typedBlockStats(Typer.scala:1056)
	at dotty.tools.dotc.typer.Typer.typedBlock(Typer.scala:1060)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2867)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2922)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2987)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2991)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3107)
	at dotty.tools.dotc.typer.Typer.$anonfun$48(Typer.scala:2295)
	at dotty.tools.dotc.typer.PrepareInlineable$.dropInlineIfError(PrepareInlineable.scala:248)
	at dotty.tools.dotc.typer.Typer.typedDefDef(Typer.scala:2295)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2835)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2921)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2987)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2991)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3013)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3063)
	at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:2500)
	at dotty.tools.dotc.typer.Typer.typedTypeOrClassDef$1(Typer.scala:2847)
	at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2851)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2921)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2987)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2991)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3013)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3063)
	at dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:2629)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2892)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2922)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2987)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:2991)
	at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3107)
	at dotty.tools.dotc.typer.TyperPhase.typeCheck$$anonfun$1(TyperPhase.scala:43)
	at dotty.tools.dotc.typer.TyperPhase.typeCheck$$anonfun$adapted$1(TyperPhase.scala:50)
	at scala.Function0.apply$mcV$sp(Function0.scala:39)
	at dotty.tools.dotc.core.Phases$Phase.monitor(Phases.scala:417)
	at dotty.tools.dotc.typer.TyperPhase.typeCheck(TyperPhase.scala:50)
	at dotty.tools.dotc.typer.TyperPhase.runOn$$anonfun$3(TyperPhase.scala:84)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.typer.TyperPhase.runOn(TyperPhase.scala:84)
	at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:234)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1328)
	at dotty.tools.dotc.Run.runPhases$1(Run.scala:245)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:253)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:262)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:68)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:262)
	at dotty.tools.dotc.Run.compileSources(Run.scala:186)
	at dotty.tools.dotc.Run.compile(Run.scala:170)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:35)
	at dotty.tools.dotc.Driver.process(Driver.scala:195)
	at dotty.tools.dotc.Driver.process(Driver.scala:163)
	at dotty.tools.dotc.Driver.process(Driver.scala:175)
	at dotty.tools.dotc.Driver.main(Driver.scala:205)
	at dotty.tools.dotc.Main.main(Main.scala)

[armanbilge]

cc @erikerlandson if you're interested :)

[erikerlandson]

yikes is that a regression in scala 3.2?

[bishabosha]

yikes is that a regression in scala 3.2?

The crash is due to the new warning messages for using patterns that are not statically guaranteed to match (such as rationalTE), so constructing that warning can be fixed