[OMPI users] ScaLAPACK + BLACS + OpenMPI

[trasz]

In case anyone had problems with getting ScaLAPACK and BLACS to work
with OpenMPI: if BLACS 'selftest' completes successfully, but ScaLAPACK's
one hangs or crashes with some weird error messages, recompile BLACS with
'TRANSCOMM = -DUseMpi2' in Bmake.inc.  It fixed the problem for me, with
scalapack-1.7.4, blacs-1.7 and openmpi-1.1.2 under FreeBSD 6.2-PRE.
This is different from what http://www.open-mpi.org/faq/?category=mpi-apps
says.