Incremental compiler error with tracked val in parent trait and skolem type

[mbovel]

Compiler version

3.6.3

Minimized code

//> using scala 3.6.3
//> using options -Yforce-sbt-phases

import language.experimental.modularity

trait T(tracked val y: Int)
class C(x: Int) extends T(x + 1)
@main def main = ()

Output

Internal error in the incremental compiler while compiling /Users/mbovel/scala-snippets-6/closure_bug.scala: Unhandled type (?1 : Int) of class class dotty.tools.dotc.core.Types$SkolemType

Seems to be reported from:

scala3/compiler/src/dotty/tools/dotc/sbt/ExtractDependencies.scala

Line 129 in f7e5df5

report.error(em"Internal error in the incremental compiler while compiling ${ctx.compilationUnit.source}: $msg", pos)

Same error when compiling with Scala CLI, without -Yforce-sbt-phases.

Expectation

No error