`RuntimeAPI.unpack` for abstract type bounds is broken since 3.0.4 (scala 2.13)

[road21]

Minimized example:

//> using scala 2.13
//> using dep "dev.zio::izumi-reflect:3.0.9"

import izumi.reflect.macrortti.LightTypeTagRef
import izumi.reflect.{Tag, TagK}
import izumi.reflect.macrortti.RuntimeAPI

trait X

type SomeType[S] <: S with X

trait RootTrait[P]
trait TestTrait[F[_]] extends RootTrait[SomeType[String]]

def foo[F[_]: TagK] =
  RuntimeAPI
    .unpack(implicitly[Tag[TestTrait[F]]].tag.ref match {
      case reference: LightTypeTagRef.AbstractReference => reference
    })

type Id[x] = x

println(foo[Id])

Output:

Exception in thread "main" java.lang.IllegalStateException: Expected applied reference but got λ %0 → 0 while processing {context::X & 0}
        at izumi.reflect.macrortti.RuntimeAPI$Rewriter.ensureApplied(RuntimeAPI.scala:203)
        at izumi.reflect.macrortti.RuntimeAPI$Rewriter.$anonfun$replaceApplied$2(RuntimeAPI.scala:135)

I understand that RuntimeAPI.unpack is low level method, but in this case this error leads to the following problem when using distage + estatico newtypes (or other newtypes with abstract type bounds of intersection types):

//> using scala 2.13
//> using dep "io.7mind.izumi::distage-core:1.2.20"

import distage.{Injector, ModuleDef, TagK}
import izumi.distage.model.plan.Roots

object Test {
  trait X

  type SomeType[S] <: S with X

  trait RootTrait[P]
  trait TestTrait[F[_]] extends RootTrait[SomeType[String]]

  object SomeModule {

    def apply[F[_]: TagK]: ModuleDef = new ModuleDef {
      make[TestTrait[F]].from { () => ??? }
    }
  }
}

type Id[x] = x

final class App

val injector: Injector[Id] = Injector[Id]()

val plan =
  injector
    .plan(Test.SomeModule.apply[Id], Roots.target[App])
    .getOrThrow()

[neko-kai]

I'll look into this ASAP.

or other newtypes with abstract type bounds of intersection types

Does that mean the issue does not reproduce without intersections? In that case it could be possible to work around the issue, for now, by using newtype from fundamentals-language [1] instead of estatico, which doesn't use intersections. It should already be on the classpath if you're using distage. Of course that's assuming you control the newtype in question and that swapping out estatico doesn't break something else.

NB: Intersections were added by estatico before 2.13 only to augment implicit search scope. Since 2.13+, the containing object of an abstract type is its companion object wrt implicit search, so intersections are unecessary in encoding after 2.13.

[road21]

Does that mean the issue does not reproduce without intersections?

Yes, it doesn't reproduce without intersections
Also it doesn't reproduce on scala 3

[geny200]

I'll look into this ASAP.

Hey, did you figure out reason? (this problem affects us)

[pshirshov]

Not yet, we are busy with other things but we'll get back to this. I think an LLM can try to pinpoint and maybe fix the problem if prompted correctly.