Open MPI is installed by the distro with headers in /usr/include $ mpif90 -showme:compile -I/some/special/path -I/usr/include -pthread -I/usr/lib/openmpi -I/some/special/path
Here's why it's a problem: HDF5 is also installed in /usr with modules at /usr/include/h5*.mod. A new HDF5 cannot be compiled using the wrappers because it will always resolve the USE statements to /usr/include which is binary-incompatible with the the new version (at a minimum, they "fixed" the size of an argument to H5Lget_info_f between 1.8.3 and 1.8.4). To build the library, the current choices are (a) get rid of the system copy before building (b) not use mpif90 wrapper I just checked that MPICH2 wrappers consistently put command-line args before the wrapper args. Jed
