No equivalence between `super` and `this` in a path, scala 2 disagrees

Compiler version

Scala 3.0.0-RC3

Minimized code

package tastytest

object SuperTypes {

  class Foo {
    final val foo: String = "Foo.foo" // must be widened type
  }

  class Bar extends Foo {

    object A {
      def unapply(a: Any) = Some[Bar.super.foo.type](Bar.this.foo)
    }

    def bar: Bar.super.foo.type = "" match { case A(x) => x }
  }

}

Output

-- [E007] Type Mismatch Error: run/src-3/tastytest/SuperTypes.scala:12:62 ------
12 |      def unapply(a: Any) = Some[Bar.super.foo.type](Bar.this.foo)
   |                                                     ^^^^^^^^^^^^
   |                                      Found:    (Bar.this.foo : String)
   |                                      Required: (Bar.super.foo : String)

Explanation
===========

I tried to show that
  (Bar.this.foo : String)
conforms to
  (Bar.super.foo : String)
but the comparison trace ended with `false`:
          
  ==> (Bar.this.foo : String)  <:  (Bar.super.foo : String)
    ==> (Bar.this.foo : String)  <:  (Bar.super.foo : String) (recurring)
      ==> (Bar.this : tastytest.SuperTypes.Bar)  <:  (Bar.super : tastytest.SuperTypes.Foo)
        ==> (Bar.this : tastytest.SuperTypes.Bar)  <:  (Bar.super : tastytest.SuperTypes.Foo) (recurring)
          ==> tastytest.SuperTypes.Bar  <:  (Bar.super : tastytest.SuperTypes.Foo) (left is approximated)
            ==> tastytest.SuperTypes.Bar  <:  (Bar.super : tastytest.SuperTypes.Foo) (recurring)
            <== tastytest.SuperTypes.Bar  <:  (Bar.super : tastytest.SuperTypes.Foo) (recurring) = false
          <== tastytest.SuperTypes.Bar  <:  (Bar.super : tastytest.SuperTypes.Foo) (left is approximated) = false
        <== (Bar.this : tastytest.SuperTypes.Bar)  <:  (Bar.super : tastytest.SuperTypes.Foo) (recurring) = false
      <== (Bar.this : tastytest.SuperTypes.Bar)  <:  (Bar.super : tastytest.SuperTypes.Foo) = false
      ==> String  <:  (Bar.super.foo : String) (left is approximated)
        ==> String  <:  (Bar.super.foo : String) (recurring)
          ==> String  <:  (Bar.super.foo : String) (recurring)
          <== String  <:  (Bar.super.foo : String) (recurring) = false
        <== String  <:  (Bar.super.foo : String) (recurring) = false
      <== String  <:  (Bar.super.foo : String) (left is approximated) = false
    <== (Bar.this.foo : String)  <:  (Bar.super.foo : String) (recurring) = false
  <== (Bar.this.foo : String)  <:  (Bar.super.foo : String) = false

The tests were made under the empty constraint
1 error found

Expectation

Compiles like in Scala 2.13.5

[smarter]

I have no idea what’s going on here so please don’t count on me to fix that any time soon 😃.

[som-snytt]

Scala 2 errors on Bar.super.foo, per spec, but what is Bar.super.foo.type? If Foo defines type Oof = foo.type, then Scala 3 is also fine with Bar.super.Oof. Is the type of a member effectively a member type? I’m recovering from covid shot nr 2, so it’s all a fog.