@ggouaillardet was right -- we should have put the
ompi_buffer_detach_f08() function in the use-mpi-f08 directory to
begin with. Putting it in the mpif-h directory made it complicated as
to whether the function would be built or not (e.g., whether weak
symbols were supported or not, whether the profiling layer was
disabled or not, ...etc.).
Just put it in the use-mpi-f08 directory and always build it (when the
mpi_f08 module is built, of course), and keep it simple.