Paul, in .../ompi/mpi/fortran/use-mpi-f08, can you create the following dumb test program, compile and run nm | grep f08 on the object :
$ cat foo.f90 program foo use mpi_f08_sizeof implicit none real :: x integer :: size, ierror call MPI_Sizeof_real_s_4(x, size, ierror) stop end program with intel compiler : $ ifort -c foo.f90 $ nm foo.o | grep f08 U mpi_f08_sizeof_mp_mpi_sizeof_real_s_4_ i am wondering whether PGI compiler adds an additional undefined reference to mpi_f08_sizeof_ ... Cheers, Gilles