https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113338
--- Comment #2 from Brad Richardson ---
The addition of CFI_cdesc_t in 2018 means it is possible to pass
non-interoperable types to C so long as it doesn't need to know anything about
its type (i.e. doesn't try to modify or copy it). And yes, in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113338
--- Comment #1 from anlauf at gcc dot gnu.org ---
NAG also rejects the code.
The code compiles with gfortran if one declares t interoperable:
type, bind(c) :: t
Note that F2008 still had:
"(5) any dummy argument without the VALUE attribute
