* pthread_once_t provides the same semantics.

* It depends on having a Fortran compiler in the first place.

* This fix is temporary in nature since the underlying problem, too tight
  integration of file I/O layer and stream abstraction, is even
  aggravated with this patch.

* Otherwise netcdf.h will define some MPI declarations.

* C != Fortran :-).

* It's already in atexit.

* This might be better addressed by calling abort(3).