She would have mpi_build_info accept a string *and* a handle, returning
another handle. The only thing you can do with this second handle is pass it
to mpi_spawn. This suggests that mpi_build_info is a middleman that can be
eliminated by passing both the original two arguments (either or both of
which could be NULL), to mpi_spawn in the first place, thus eliminating the
function mpi_build_info (and mpi_free_info!)
Rusty