ExplicitOuter crash with local class defined in val in trait if the local class extends a path-dependent class

[smarter]

class Outer {
  class Inner
}

trait MustBeATrait {
  val o = new Outer
  val inner = new o.Inner {}
}

fails with assertion failed: asTerm called on not-a-Term val <none> somewhere in ExplicitOuter.
Stack trace: https://gist.github.com/smarter/992bb93f2d0f2705a6a6

[smarter]

Note that there's no crash if val inner = is removed or replaced by def inner =.

[smarter]

More info, if we print the ctx.log calls in ExplicitOuter:

computing outerpath to trait MustBeATrait from List(method <init>, method inner, method inner, class MustBeATrait, class MustBeATrait, module class <empty>, module class <root>, module class <root>, module class <root>, module class <root>, module class <root>, module class <root>, module class <root>, val <none>, val <none>, val <none>, val <none>)
outer to trait MustBeATrait of this: Outer.this.Inner{...}(this), looking for MustBeATrait$~$anon$$$outer in anonymous class Outer.this.Inner{...}
outer to trait MustBeATrait of this.MustBeATrait$~$anon$$$outer(): MustBeATrait, looking for MustBeATrait$$$outer in trait MustBeATrait
computing outerpath to anonymous class Outer.this.Inner{...} from List(class MustBeATrait, class MustBeATrait, class MustBeATrait, module class <empty>, module class <root>, module class <root>, module class <root>, module class <root>, module class <root>, module class <root>, module class <root>, val <none>, val <none>, val <none>, val <none>)
outer to anonymous class Outer.this.Inner{...} of this: MustBeATrait(MustBeATrait.this), looking for MustBeATrait$$$outer in trait MustBeATrait

The last two lines do not appear and there's no crash if we replace val inner = by def inner =

[smarter]

It also happens with non-anonymous local classes:

class Outer {
  class Inner
}

trait MustBeATrait {
  val o = new Outer
  val inner = {
    class A extends o.Inner
    new A
  }
}