GFortran 15 bug

issue_interface.f90

module odeint_allroutines_sub
    implicit none

    abstract interface
        subroutine compute_derivative(x, y, dydx)
            real(8), intent(in) :: x
            real(8), intent(in) :: y(:)
            real(8), intent(out) :: dydx(:)
        end subroutine compute_derivative
    end interface

contains

    subroutine odeint(y, nvar, x1, x2, derivs)

        integer, intent(in) :: nvar
        real(8), intent(inout) :: y(nvar)
        real(8), intent(in) :: x1, x2
        procedure(compute_derivative) :: derivs

        real(8) :: dydx(nvar)

        call derivs(0d0, y, dydx)
        call rkqs(derivs)

    end subroutine odeint

    subroutine rkqs(derivs)

        procedure(compute_derivative) :: derivs

    end subroutine rkqs
end module odeint_allroutines_sub

GCC GFortran 15.1.1 20250425 on Arch Linux.

gfortran -Wexternal-argument-mismatch -c issue_interface.f90

fails with

issue_interface.f90:24:18:

   24 |         call rkqs(derivs)
      |                  1
Error: Interface mismatch in dummy procedure ‘derivs’ at (1): Shape mismatch in argument 'y'

The error disappears when the warning flag is not passed, and is also triggered by -Wall in this version. Expected behavior would be warnings (if even applicable, I think the code is fine), not errors appearing. Version 14.2.1 20250207 that doesn't support -Wexternal-argument-mismatch yet works fine also with -Wall.