Installation using Spack¶
This guide will install Bohrium using the Spack package manager.
Why use Spack?¶
Spack is a package management tool tailored specifically for supercomputers with a rather dated software stack. It allows to install and maintain packages, starting only from very few dependencies: Pretty much just python2.6, git, curl and some c++ compiler are all that’s needed for the bootstrap.
Needless to say that the request for installing a particular package automatically yields the installation of all dependencies with exactly the right version and configurations. If this causes multiple versions/configurations of the same package to be required, this is no problem and gets resolved automatically, too. As a bonus on top, using an installed package later is super easy as well due to an automatic generation of module files, which set the required environment up.
First step is to clone and setup Spack:
git clone https://github.com/llnl/spack.git
Afterwards the installation of Bohrium is instructed:
spack install bohrium
This step will take a while, since Spack will download the sources of all dependencies, unpack, configure and compile them. But since everything happens in the right order automatically, you could easily do this over night.
That’s it. If you want to use Bohrium, setup up Spack as above, then load the required modules:
spack module loads -r bohrium > /tmp/bohrium.modules
and you are ready to go as the shell environment now contains all required variables (LD_LIBRARY_PATH, PATH, CPATH, PYTHONPATH, …) to get going.
If you get some errors about the command module not being found, you need to install the Spack package environment-modules beforehand. Again, just a plain:
spack install environment-modules
is enough to achieve this.
Tuning the installation procedure¶
Most importantly the so-called spec allows to specify features or requirements with respect to versions and dependencies, that should be enabled or disabled when building the package. For example:
spec install bohrium~cuda~opencl
Will install Bohrium without CUDA or OpenCL support, which has a dramatic impact on the install time due to the reduced amount of dependencies to be installed. On the other hand:
spec install bohrium@develop
will install specifically the development version of Bohrium. This the current HEAD of the master branch in the github repository. One may also influence the versions of the dependencies by themselves. For example:
spec install bohrium+python^python@3:
will specifically compile Bohrium with a python version larger than 3.
The current list of features the Bohrium package has to offer can be listed by the command:
spack info bohrium
and the list of dependencies which will be installed by a particlar spec can be easily reviewed by something like:
spack spec bohrium@develop~cuda~opencl