It is impossible to get algebraic multigrid support on mac

[Sergey Alyaev]

This is a branch that somehow popped up during the discussion of the bug at
https://bugs.launchpad.net/dorsal/+bug/704076

It is really crucial for performance and usability of FEniCS to be able to use state-of-the-art linear algebra tools.
So far it says that PETSc is compiled without multigrid support.

It seems that on Mac OS X dorsal installs "petsccore" vs on linux it is fully functional "petsc".
Trilinos is not installed as well but is not installed on linux either. I am not sure which functionality it provides.

[Johannes Ring (johannr)]

A simple solution to this problem is to install the prebuilt gfortran binaries located at

    http://gcc.gnu.org/wiki/GFortranBinaries#MacOS

This will install gfortran into /usr/local/gfortran with a symlink /usr/local/bin/gfortran to the gfortran binary. One can then replace "petsccore" with "petsc" in the platform file for Snow Leopard to get PETSc with all the goodies (Hypre, MUMPS, etc.).

I also have a patch for building Trilinos on Mac (if anyone is interested), but I get errors when running DOLFIN with this.

[Sergey Alyaev (cobxo3bot)]

What functionality does Trilinos provide?

[Johannes Ring (johannr)]

Trilinos is one of the la backends supported by DOLFIN.

[Johannes Ring (johannr)]

I forgot to say that one also has to set Dorsal to build OpenMPI before switching from "petsccore" to "petsc". That is, put "openmpi" (without the quotes) at the top of the list of packages in the platform file.