[petsc-dev] Consider changing default installation instructions so that OS X users don't mix their MPI metaphors

[Satish Balay]

On Sun, 5 Jun 2011, Aron Ahmadia wrote:

> OS X and many Linux distributions now come with a system MPI.  If you
> install by downloading MPICH and then use 'mpirun', your code will never run
> in parallel, at best, or do something completely unexpected, at worst.
> 
> The current default instructions are:
> 
> export PETSC_DIR=$PWD
> ./config/configure.py --with-cc=gcc --with-fc=gfortran
> --download-f-blas-lapack=1 --download-mpich=1
> make all test
> 
> I think OS X-specific instructions that don't install MPICH or that
> explicitly suggest appending $PETSC_DIR/$PETSC_ARCH/bin to your path when
> running parallel jobs after installing mpich will help prevent users from
> falling into this trap.

The above are generic instructions which work everywere. There are
more specific examples further down - which one can check.

And OSX has broken MPI to start with - and even if we pander to that -
most users will have issues. The best thing an OSX user can do is
delete those files.  [yeah - one has to manually delete them - one
can't uninstall them]

Satish