Quoted matching with abstract type leads to unresolved symbols when pickling

[szeiger]

This crashes the compiler. Tested with 0.25.0 and 0.26.0-RC1.

Minimized code

import scala.quoted._

sealed trait Coll[A] {
  type C[X] // must be abstract
  def map[B]: C[Any] // needs both the type param and a return type that refers to C 
}

object QuoteTest {
  def compile[T : Type](expr: Expr[T])(using QuoteContext): Expr[Any] = expr match {
    case '{ ($coll: Coll[$foo]).map[$b] } => '{ null }
  }
}

Output

[error] java.lang.AssertionError: assertion failed: unresolved symbols: value foo(line 9) when pickling /mnt/c/Users/szeiger/code/dottyquery/src/main/scala/QuoteTest.scala
[error] dotty.DottyPredef$.assertFail(DottyPredef.scala:17)
[error] dotty.tools.dotc.core.tasty.TreePickler.pickle(TreePickler.scala:738)
[error] dotty.tools.dotc.transform.Pickler.run$$anonfun$9$$anonfun$8(Pickler.scala:63)
[error] dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] scala.collection.immutable.List.foreach(List.scala:333)
[error] dotty.tools.dotc.transform.Pickler.run$$anonfun$1(Pickler.scala:87)
[error] dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] scala.collection.immutable.List.foreach(List.scala:333)
[error] dotty.tools.dotc.transform.Pickler.run(Pickler.scala:87)
[error] dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:318)
[error] scala.collection.immutable.List.map(List.scala:246)
[error] dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:319)
[error] dotty.tools.dotc.transform.Pickler.runOn(Pickler.scala:91)
[error] dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:180)
[error] dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
[error] dotty.tools.dotc.Run.runPhases$5(Run.scala:190)
[error] dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:198)
[error] dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:64)
[error] dotty.tools.dotc.Run.compileUnits(Run.scala:205)
[error] dotty.tools.dotc.Run.compileSources(Run.scala:142)
[error] dotty.tools.dotc.Run.compile(Run.scala:124)
[error] dotty.tools.dotc.Driver.doCompile(Driver.scala:38)
[error] dotty.tools.dotc.Driver.process(Driver.scala:194)
[error] dotty.tools.dotc.Main.process(Main.scala)

[nicolasstucki]

Slight minimization

import scala.quoted._

trait Coll[A] {
  type C[X] // must be abstract
  def map[B]: C[Any] // needs both the type param and a return type that refers to C
}

object QuoteTest {
  def compile(expr: Expr[Any])(using QuoteContext): Expr[Any] = expr match {
    case '{ (??? : Coll[$y]).map[$b] } => ???
  }
}