Platform configurations for Mochi

This repository provides Spack configuration files, example job scripts, and notes about building and running Mochi-based codes on various platforms. Please refer to the subdirectory for your platform of interest for more information.

The generic subdirectory contains a minimal Spack environment example that can be used as a starting point for systems for which there is no existing recipe.

Using spack.yaml files

Each platform subdirectory in this repository provides a spack.yaml file. A spack.yaml file fully describes a Spack environment, including system-provided packages and compilers. It does so independently of any compilers.yaml or packages.yaml files installed in ~/.spack, thereby preventing interference with user-specific spack configurations as much as possible.

You may use spack.yaml files to create a Spack environment in which Mochi packages will be installed.

If you don't have Spack installed on your platform, clone it and set it up as follows.

NOTE: as of June 2025, the development branch of Spack is aligned with the upcoming version 1.0 of Spack. This version introduces numerous improvements, but also some incompatibilities with older environment configurations. For now, we recommend using a version of Spack prior to 1.0 to ensure compabitility with the recipes provided in this repository:

$ git clone --branch v0.23.1 https://github.com/spack/spack.git
$ . spack/share/spack/setup-env.sh

Remember that the second line needs to be executed every time you open a new terminal; it may be helpful to create an alias in your bashrc file as a shortcut.

You will then need to clone mochi-spack-packages, which contains the Mochi packages.

$ git clone https://github.com/mochi-hpc/mochi-spack-packages.git

Now clone the present repository and cd into the subdirectory relevant to your platform. For example:

$ git clone https://github.com/mochi-hpc-experiments/platform-configurations.git
$ cd platform-configurations/ANL/Bebop

Then, execute the following commands (changing myenv into an appropriate name for your environment).

$ spack env create myenv spack.yaml
$ spack env activate myenv
$ spack repo add /where/you/cloned/mochi-spack-packages

Change to a directory outside of the platform-configurations folders and activate the environment as follows.

You may now add specs to your environment. For instance if you want to install Margo, execute the following command.

$ spack add mochi-margo

If the spack.yaml file provides multiple compilers and you want to use another than the default one, specify the compiler explicitely, for example:

$ spack add mochi-margo %gcc@8.2.0

Note that the spack.yaml file you used may already have a spec added as an example (usually mochi-margo). You can remove it as follows.

$ spack rm mochi-margo

Once you have added the specs you need in your environment, install everything by executing the following command.

$ spack install

You may add more specs later on. For more information on how to manage Spack environments, please refer to the Spack documentation.

Contributing to this repository

Should you want to contribute a spack.yaml for a particular machine, please submit a merge request with it, and ensure the following.

• The spack.yaml file should contain the compiler(s) that have been tested and confirmed to work with Mochi packages.
• The spack.yaml file should try to list system-provided packages, in particular packages used for building (cmake, autoconf, etc.), and relevant system-provided MPI implementations.
  • Note that this must be done manually. Spack provides a spack external find command that can be used to locate a subset of system packages, but it does not populate the spack.yaml file.
• The spack.yaml file should contain the relevant variants for packages, in particular the transport methods to use with libfabric.
• The path to the spack.yaml file should be of the form <institution>/<platform>/spack.yaml.
• Please make sure that your spack.yaml is a reliable way to work with Mochi on the target platform, other people will rely on it!

You can also contribute changes to existing spack.yaml files, in particular to add working compilers, system packages, etc. As always, please test that new setups work before creating a merge request.