minor SUBMODULE bug

module WhatLineIsTheError
    implicit none
    interface
    module function thing(it)
        implicit none
        integer             :: thing
        integer, intent(in) :: it
    end function
    end interface
end module WhatLineIsTheError

submodule(WhatLineIsTheError) subm1_WhatLineIsTheError
    implicit none

    contains
    module function thing(it)
        implicit none
        integer             :: thing
        integer, intent(in) :: it
    end function
end submodule subm1_WhatLineIsTheError

Compiling with Intel(R) Visual Fortran Compiler 17.0.4.210 [IA-32]...
warning #6178: The return value of this FUNCTION has not been defined.   [THING]

It is but a minor problem. The error has no line association to the source so clicking it takes you to line 1. There have been other errors in SUBMODULE of this type that have been fixed, I suspect there are possibly a number of similar errors of the same class.