Spack

Spack is a package manager which is very useful to install scientific software.

Preparing a Linux system

We will install the gcc and gfortran compilers from the system package manager. Dont install anything else since they will be installed using Spack. There are some instructions for OpenSUSE and Debian. Since Spack installs its own MPI library, it is best to uninstall any MPI you may have installed from your system package manager, since having multiple MPI around can cause problems.

Preparing a Mac system

• Make sure you have latest command line tools (XCode is not required).
• Install gcc from Homebrew which also provides the gfortran compiler. See here.

Install Spack

We will install Spack into SPACK_ROOT directory.

export SPACK_ROOT=/path/to/spack

Now get Spack

git clone https://github.com/spack/spack.git $SPACK_ROOT

You can add following lines to your .bashrc or .profile file

export SPACK_ROOT=/path/to/spack
. ${SPACK_ROOT}/share/spack/setup-env.sh

Here are some useful Spack commands

spack list intel          -- search package names containing intel
spack info gcc            -- show information for package gcc
spack find                -- shows installed packages
spack compilers           -- show available compilers
spack location -i openmpi -- show location of openmpi
spack repo update         -- update packages repo

Setup compilers by running

spack compiler find

which creates the file packages.yaml in your $HOME/.spack directory. Edit it if needed, remove compilers you dont want to use

To this file, add some variants of other packages you want to install, my example is here.

wget https://raw.githubusercontent.com/cpraveen/cfdlab/master/configs/spack_packages.yaml
grep -v packages: spack_packages.yaml >> $HOME/.spack/packages.yaml

You need to choose providers for mpi, blas and lapack in your packages.yaml file. E.g., choose [openmpi] for mpi and [openblas] for blas and lapack.

To see all available options for some virtual packages,

spack providers mpi
spack providers blas
spack providers lapack

Install softwares

I install deal.II and its dependencies which provides all the softwares that I need for my work. Since I like to compile deal.II myself, I will install only dependencies. But first check that all variants you need are correct by running

spack spec --fresh -I dealii
spack spec --reuse -I dealii # --reuse is the default

Select one of --fresh or --reuse; the second is the default and will use already installed packages even if newer versions are available.

If this is ok, then we install

spack install -j4 --fail-fast --only dependencies dealii  #  Add --fresh if needed

The flag -j4 means that four processes will be used while compiling; increase this if you have more cores on your computer. If you primarily use Petsc and Metis, and dont need other stuff, then do

spack spec petsc
spack install -j4 --fail-fast petsc

Now create a Spack view by running the script spack_view.sh which will install symlinks into SPACK_VIEW directory.

export SPACK_VIEW=/path/to/spack/view # Add to .bashrc or .profile file
sh /path/to/spack_view.sh /path/to/spack/view/dir

If the SPACK_VIEW directory is in not in your home directory, then set ownership, e.g.,

sudo mkdir $SPACK_VIEW
sudo chown praveen:users $SPACK_VIEW

and then run the spack_view.sh script. This is useful on a Linux computer where I want to install the software for all users.

Here is a sample spack_view.sh script which you can edit for your needs.

You can set some variables in your .bashrc or .profile file

export PETSC_DIR=$SPACK_VIEW
export SLEPC_DIR=$SPACK_VIEW
export METIS_DIR=$SPACK_VIEW
export HDF5_DIR=$SPACK_VIEW
export PATH=$SPACK_VIEW/bin:$PATH

which can be used in your makefiles for compiling your applications.

Upgrading

When I want to upgrade, I usually reinstall everything from scratch.

cd $SPACK_ROOT
git pull
spack repo update

Update your packages.yaml file if needed. Verify that you get all package variants that you need. Then continue

spack uninstall --all
spack install -j4 --fail-fast --only dependencies dealii

Now we create a new spack view,

sh /path/to/spack_view.sh /path/to/install/spack/view

Finding info on an installed package

$ spack find -lv petsc
==> 1 installed package
-- linux-opensuse_tumbleweed20200511-broadwell / gcc@9.3.1 ------
c67eysz petsc@3.13.1

Find more about installed petsc

spack spec /c67eysz

Compiling deal.II using spack packages

If you want to compile deal.II on your own, then I have a cmake configure script here.