Fortran cannot compile call to procedure on abstract parent type

Question

I'm working on a large project where a particular group of objects has several layers of inheritance. It's common for an object to have a method which first call's the parent object's version of that method, then performs some additional work that's specific to the child.

While this is a pattern I've followed many times, I recently discovered that if the parent class is ABSTRACT, gfortran 8.3.0 does not compiler. Here is a MWE:

MODULE typeDef
TYPE,ABSTRACT :: parent
  CONTAINS
    PROCEDURE :: testFoo => testFooParent
ENDTYPE parent
TYPE,EXTENDS(parent) :: child
  CONTAINS
    PROCEDURE :: testFoo => testFooChild
ENDTYPE child

CONTAINS
  SUBROUTINE testFooParent(this)
    CLASS(parent),INTENT(INOUT) :: this

    WRITE(*,*) 'parent'
  ENDSUBROUTINE testFooParent
  SUBROUTINE testFooChild(this)
    CLASS(child),INTENT(INOUT) :: this

    CALL this%parent%testFoo()
    WRITE(*,*) 'child'
  ENDSUBROUTINE testFooChild
ENDMODULE typeDef
PROGRAM bug

ENDPROGRAM

The error I receive is here:

bug.f90:20:13:

     CALL this%parent%testFoo()
             1
Error: Base object for type-bound procedure call at (1) is of ABSTRACT type ‘parent’

I am aware of no such reason that this should not work, but perhaps I've missed something in the standard? If anyone can confirm for me that this is a bug before I go submit a potentially stupid bug report, that would be very helpful.

I am currently simply duplicating the parent class's behavior inside the child class's implementation. In this particular case, that's not a big deal, but it could easily cause problems down the road.