Dependent function type with a wildcard argument crashes the compiler

[clavigne]

Compiler version

3.3.0

Minimized code

trait F:
  type A

type G = (f: _ <: F) => f.A

Output

Throws a MatchError in the compiler.

Stack trace:

Crashes with stack trace,

scala.MatchError: dotty.tools.dotc.core.Types$UnspecifiedErrorType$@3db432c2 (of class dotty.tools.dotc.core.Types$UnspecifiedErrorType$) while running pickler on rs$line$1
Exception in thread "main" scala.MatchError: dotty.tools.dotc.core.Types$UnspecifiedErrorType$@3db432c2 (of class dotty.tools.dotc.core.Types$UnspecifiedErrorType$)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleNewType(TreePickler.scala:295)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleType(TreePickler.scala:162)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:626)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$20(TreePickler.scala:642)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:642)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:638)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTpt(TreePickler.scala:320)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:339)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:584)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleStats$$anonfun$2(TreePickler.scala:374)
        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.core.tasty.TreePickler.pickleStats(TreePickler.scala:374)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:608)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:338)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:584)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleStats$$anonfun$2(TreePickler.scala:374)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleStats(TreePickler.scala:374)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:624)
        at dotty.tools.dotc.core.tasty.TreePickler.pickle$$anonfun$1(TreePickler.scala:798)
        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.core.tasty.TreePickler.pickle(TreePickler.scala:805)
        at dotty.tools.dotc.transform.Pickler.run$$anonfun$1$$anonfun$1(Pickler.scala:90)
        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.transform.Pickler.run$$anonfun$1(Pickler.scala:142)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.transform.Pickler.run(Pickler.scala:142)
        at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:324)
        at scala.collection.immutable.List.map(List.scala:246)
        at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:328)
        at dotty.tools.dotc.transform.Pickler.runOn(Pickler.scala:150)
        at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:247)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1321)
        at dotty.tools.dotc.Run.runPhases$1(Run.scala:263)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:271)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:280)
        at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:280)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:201)
        at dotty.tools.repl.ReplCompiler.compile(ReplCompiler.scala:87)
        at dotty.tools.repl.ReplDriver.compile(ReplDriver.scala:307)
        at dotty.tools.repl.ReplDriver.interpret(ReplDriver.scala:269)
        at dotty.tools.repl.ReplDriver.run$$anonfun$1(ReplDriver.scala:177)
        at dotty.tools.repl.ReplDriver.withRedirectedOutput(ReplDriver.scala:211)
        at dotty.tools.repl.ReplDriver.runBody$$anonfun$1(ReplDriver.scala:185)
        at dotty.tools.runner.ScalaClassLoader$.asContext(ScalaClassLoader.scala:80)
        at dotty.tools.repl.ReplDriver.runBody(ReplDriver.scala:185)
        at dotty.tools.repl.ReplDriver.run(ReplDriver.scala:178)
        at dotty.tools.repl.ReplDriver.interpretCommand(ReplDriver.scala:479)
        at dotty.tools.repl.ReplDriver.interpret(ReplDriver.scala:276)
        at dotty.tools.repl.ReplDriver.loop$1(ReplDriver.scala:169)
        at dotty.tools.repl.ReplDriver.runUntilQuit$$anonfun$1(ReplDriver.scala:172)
        at dotty.tools.repl.ReplDriver.withRedirectedOutput(ReplDriver.scala:211)
        at dotty.tools.repl.ReplDriver.runBody$$anonfun$1(ReplDriver.scala:185)
        at dotty.tools.runner.ScalaClassLoader$.asContext(ScalaClassLoader.scala:80)
        at dotty.tools.repl.ReplDriver.runBody(ReplDriver.scala:185)
        at dotty.tools.repl.ReplDriver.runUntilQuit(ReplDriver.scala:172)
        at dotty.tools.repl.ReplDriver.tryRunning(ReplDriver.scala:134)
        at dotty.tools.repl.Main$.main(Main.scala:7)
        at dotty.tools.repl.Main.main(Main.scala)