assertion failure in PatternMatcher when returning dependent NamedTuple.From #24504
Description
Compiler version
3.7.4, 3.8.1-RC1-bin-20251121-0470ec1-NIGHTLY,
Minimized code
object Unpack {
trait Expr[T] {
type Fields = NamedTuple.From[T]
}
final case class Pair(a: Int, b: Int)
def unapply(e: Expr[Pair]): e.Fields = ???
val x: Expr[Pair] = ???
x match {
case Unpack(_, _) => ???
}
}
Output (click arrow to expand)
scala-cli -S 3.nightly i23158.scala
Compiling project (Scala 3.8.1-RC1-bin-20251121-0470ec1-NIGHTLY, JVM (21))
Error compiling project (Scala 3.8.1-RC1-bin-20251121-0470ec1-NIGHTLY, JVM (21))
Error: java.lang.AssertionError: assertion failed
at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:13)
at dotty.tools.dotc.transform.PatternMatcher$Translator.unapplyPlan$1$$anonfun$1(PatternMatcher.scala:426)
at dotty.tools.dotc.transform.PatternMatcher$Translator.letAbstract(PatternMatcher.scala:123)
at dotty.tools.dotc.transform.PatternMatcher$Translator.unapplyPlan$1(PatternMatcher.scala:409)
at dotty.tools.dotc.transform.PatternMatcher$Translator.patternPlan(PatternMatcher.scala:493)
at dotty.tools.dotc.transform.PatternMatcher$Translator.caseDefPlan(PatternMatcher.scala:539)
at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan$$anonfun$1$$anonfun$1(PatternMatcher.scala:553)
at scala.collection.immutable.List.foldRight(List.scala:346)
at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan$$anonfun$1(PatternMatcher.scala:552)
at dotty.tools.dotc.transform.PatternMatcher$Translator.letAbstract(PatternMatcher.scala:123)
at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan(PatternMatcher.scala:550)
at dotty.tools.dotc.transform.PatternMatcher$Translator.translateMatch(PatternMatcher.scala:1138)
at dotty.tools.dotc.transform.PatternMatcher.transformMatch(PatternMatcher.scala:53)
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.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$$anonfun$1(Phases.scala:406)
at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
at scala.collection.immutable.List.foreach(List.scala:327)
at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:399)
at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:380)
at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1327)
at dotty.tools.dotc.Run.runPhases$1(Run.scala:373)
at dotty.tools.dotc.Run.compileUnits$$anonfun$1$$anonfun$2(Run.scala:420)
at dotty.tools.dotc.Run.compileUnits$$anonfun$1$$anonfun$adapted$1(Run.scala:420)
at scala.Function0.apply$mcV$sp(Function0.scala:45)
at dotty.tools.dotc.Run.showProgress(Run.scala:482)
at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:420)
at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:432)
at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:69)
at dotty.tools.dotc.Run.compileUnits(Run.scala:432)
at dotty.tools.dotc.Run.compileSources(Run.scala:319)
at dotty.tools.dotc.Run.compile(Run.scala:304)
at dotty.tools.dotc.Driver.doCompile(Driver.scala:38)
at dotty.tools.xsbt.CompilerBridgeDriver.run(CompilerBridgeDriver.java:141)
at dotty.tools.xsbt.CompilerBridge.run(CompilerBridge.java:22)
at sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:91)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.compileSources$1(BloopHighLevelCompiler.scala:148)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.$anonfun$compile$9(BloopHighLevelCompiler.scala:181)
at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.$anonfun$compile$1(BloopHighLevelCompiler.scala:73)
at bloop.tracing.NoopTracer$.trace(BraveTracer.scala:53)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.timed$1(BloopHighLevelCompiler.scala:72)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.$anonfun$compile$8(BloopHighLevelCompiler.scala:181)
at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
at monix.eval.internal.TaskRunLoop$.startFull(TaskRunLoop.scala:81)
at monix.eval.internal.TaskRestartCallback.syncOnSuccess(TaskRestartCallback.scala:101)
at monix.eval.internal.TaskRestartCallback.onSuccess(TaskRestartCallback.scala:74)
at monix.eval.internal.TaskExecuteOn$AsyncRegister$$anon$1.run(TaskExecuteOn.scala:71)
at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1423)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)
Error: Unexpected error when compiling scala3_14f7c54d30-6d8fd47f1a: java.lang.AssertionError: assertion failed
at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:13)
at dotty.tools.dotc.transform.PatternMatcher$Translator.unapplyPlan$1$$anonfun$1(PatternMatcher.scala:426)
at dotty.tools.dotc.transform.PatternMatcher$Translator.letAbstract(PatternMatcher.scala:123)
at dotty.tools.dotc.transform.PatternMatcher$Translator.unapplyPlan$1(PatternMatcher.scala:409)
at dotty.tools.dotc.transform.PatternMatcher$Translator.patternPlan(PatternMatcher.scala:493)
at dotty.tools.dotc.transform.PatternMatcher$Translator.caseDefPlan(PatternMatcher.scala:539)
at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan$$anonfun$1$$anonfun$1(PatternMatcher.scala:553)
at scala.collection.immutable.List.foldRight(List.scala:346)
at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan$$anonfun$1(PatternMatcher.scala:552)
at dotty.tools.dotc.transform.PatternMatcher$Translator.letAbstract(PatternMatcher.scala:123)
at dotty.tools.dotc.transform.PatternMatcher$Translator.matchPlan(PatternMatcher.scala:550)
at dotty.tools.dotc.transform.PatternMatcher$Translator.translateMatch(PatternMatcher.scala:1138)
at dotty.tools.dotc.transform.PatternMatcher.transformMatch(PatternMatcher.scala:53)
at dotty.tools.dotc.transform.MegaPhase.goMatch(MegaPhase.scala:816)
at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:383)
at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:454)
at dotty.tools.dotc.transform.MegaPhase.loop$1(MegaPhase.scala:465)
at dotty.tools.dotc.transform.MegaPhase.transformStats(MegaPhase.scala:465)
at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:376)
at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:454)
at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:272)
at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:452)
at dotty.tools.dotc.transform.MegaPhase.loop$1(MegaPhase.scala:465)
at dotty.tools.dotc.transform.MegaPhase.transformStats(MegaPhase.scala:465)
at dotty.tools.dotc.transform.MegaPhase.mapPackage$1(MegaPhase.scala:396)
at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:399)
at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:454)
at dotty.tools.dotc.transform.MegaPhase.transformUnit(MegaPhase.scala:481)
at dotty.tools.dotc.transform.MegaPhase.run(MegaPhase.scala:493)
at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:406)
at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
at scala.collection.immutable.List.foreach(List.scala:327)
at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:399)
at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:380)
at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1327)
at dotty.tools.dotc.Run.runPhases$1(Run.scala:373)
at dotty.tools.dotc.Run.compileUnits$$anonfun$1$$anonfun$2(Run.scala:420)
at dotty.tools.dotc.Run.compileUnits$$anonfun$1$$anonfun$adapted$1(Run.scala:420)
at scala.Function0.apply$mcV$sp(Function0.scala:45)
at dotty.tools.dotc.Run.showProgress(Run.scala:482)
at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:420)
at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:432)
at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:69)
at dotty.tools.dotc.Run.compileUnits(Run.scala:432)
at dotty.tools.dotc.Run.compileSources(Run.scala:319)
at dotty.tools.dotc.Run.compile(Run.scala:304)
at dotty.tools.dotc.Driver.doCompile(Driver.scala:38)
at dotty.tools.xsbt.CompilerBridgeDriver.run(CompilerBridgeDriver.java:141)
at dotty.tools.xsbt.CompilerBridge.run(CompilerBridge.java:22)
at sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:91)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.compileSources$1(BloopHighLevelCompiler.scala:148)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.$anonfun$compile$9(BloopHighLevelCompiler.scala:181)
at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.$anonfun$compile$1(BloopHighLevelCompiler.scala:73)
at bloop.tracing.NoopTracer$.trace(BraveTracer.scala:53)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.timed$1(BloopHighLevelCompiler.scala:72)
at sbt.internal.inc.bloop.internal.BloopHighLevelCompiler.$anonfun$compile$8(BloopHighLevelCompiler.scala:181)
at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
at monix.eval.internal.TaskRunLoop$.startFull(TaskRunLoop.scala:81)
at monix.eval.internal.TaskRestartCallback.syncOnSuccess(TaskRestartCallback.scala:101)
at monix.eval.internal.TaskRestartCallback.onSuccess(TaskRestartCallback.scala:74)
at monix.eval.internal.TaskExecuteOn$AsyncRegister$$anon$1.run(TaskExecuteOn.scala:71)
at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1423)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)
Compilation failed