Extension method lookup failure when the receiver type is path-dependent on a using parameter and the extension comes from a given looked up based on the implicit scope of the type of the receiver

[smarter]

Compiler version

3.3.1

Minimized code

trait Context:
  type Elem[T]

trait TypeClass[T]:
  extension (using nb: Context)(x: nb.Elem[T])
    def tcMeth: T


class Bla
object Bla:
  given fb: TypeClass[Bla] = ???

class Wrapper[T]
object Wrapper:
  given fa[T](using TypeClass[T]): TypeClass[Wrapper[T]] = ???


object Test:
  def test1(using nb: Context) =
    val x1: nb.Elem[Bla] = ???
    val x2: nb.Elem[Wrapper[Bla]] = ???
    x1.tcMeth // ok
    x2.tcMeth // error
    summon[TypeClass[Wrapper[Bla]]].tcMeth(x2) // ok

  def test2(using nb: Context, tc: TypeClass[Wrapper[Bla]]) =
    val y: nb.Elem[Wrapper[Bla]] = ???
    y.tcMeth // ok

Output

-- [E008] Not Found Error: tests/pos/extgiven.scala:23:7 -----------------------
23 |    x2.tcMeth // error
   |    ^^^^^^^^^
   |    value tcMeth is not a member of nb.Elem[Wrapper[Bla]].
   |    An extension method was tried, but could not be fully constructed:
   |
   |        Wrapper.fa[T](/* missing */summon[TypeClass[T]]).tcMeth()

Expectation

x2.tcMeth should typecheck since summon[TypeClass[Wrapper[Bla]]].tcMeth(x2) does typecheck and the summoned instance is Wrapper.fa which is in the implicit scope of the type of x2.