https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85983
--- Comment #2 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> --- Removing the assert at interface.c:4748 seems to fix this, giving the following error: z2.f03:14:16: subroutine s2 (dtv, unit) 1 Error: Too few dummy arguments in DTIO procedure ‘s2’ at (1)