[MITgcm-support] mpi=PATH option for genmake2 is nonfunctional

[Eric Firing]

There is a related post: 
http://mitgcm.org/pipermail/mitgcm-support/2013-September/008513.html in 
which this problem was encountered, but not fully explained.

The genmake2 'mpi=PATH' option as documented in the --help output is 
nonfunctional.  It sets the internal MPIPATH variable to PATH, but then 
never does anything with it.  It is actually needed only to set the 
include directory search so that mpif.h will be found.

A workaround for a stock ubuntu installation is to set the CPATH 
variable, e.g.,

export CPATH=/usr/lib/openmpi/include

before calling genmake2.

Eric