http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47495
--- Comment #4 from Ralf Wildenhues <rwild at gcc dot gnu.org> 2011-01-29 11:48:04 UTC --- For starters it would be nice if gfortran would even document its precise semantics for when module files are created/updated/etc. I'm sure these semantics are not identical across Fortran compilers. This is PR 42607.