Skip to content

Argonne Leadership Computing Facility

Spack PE

The Spack PE is a software stack which provides various build tools, utilities, and libraries. The Spack PE consists of two parts: spack-pe-gcc and spack-pe-oneapi. spack-pe-gcc contains commonly used software packages compiled with GCC. spack-pe-oneapi is based on the E4S Project and provides performant HPC libraries built with the OneAPI PE. spack-pe-oneapi is dependent on both spack-pe-gcc and the OneAPI PE.

Using software from the Spack PE

Currently the Spack PE is installed in /soft. Packages in the Spack PE can be accessed via modulefile:

$ module use /soft/modulefiles
$ module load spack-pe-gcc
$ module load cmake
$ which cmake

The above example loads cmake into the current environment. The spack-pe-gcc module adds paths to the user's MODULEPATH; individual packages are subsequently loaded through the newly available modules. The full list of available packages can be viewed by running module avail. Packages are loaded in the same way from spack-pe-oneapi, with the caveat that spack-pe-oneapi is tied to specific versions of oneapi.

Inspecting packages

When a module within the Spack PE is loaded, several environment variables are updated to integrate the package into the user's environment. Additionally, the PACKAGE_ROOT variable is set to contain the path to the installation prefix of the package. For example, continuing from the cmake example above:

$ echo $CMAKE_ROOT
bin  doc  share

This variable can be used to inspect software installations and find header or library paths. Additionally, Spack packages have a .spack directory in the installation prefix which contains build logs and information on configure and build options.

Building software with Spack

Spack is a powerful package manager designed for HPC. The Spack PE is installed and managed with Spack; users can also install Spack in their own home or project directory to manage their software builds. Spack has a steep learning curve, but it may benefit workflows involving frequent builds with complex dependencies.

For users who wish to use Spack to install their own software, we provide configuration files corresponding to the Spack PE deployments. These configuration files can be found in /soft/packaging/spack/settings, organized into directories by Aurora PE and Spack PE versions. Not all of these settings will be useful for all builds and it is not recommended to adopt these wholesale as global settings. The recommended method is to include these settings ad hoc in a spack environment to control what information spack uses for its builds. However, we highly recommend using or adapting the aurora_packages_{spack-pe-version}.yaml and compilers_{spack-pe-version}.yaml configurations, since these configurations are essential for Spack to recognize the OneAPI compiler and associated Aurora PE components such as MPICH.

Support requests and feedback for ALCF-specific issues should be directed to For general spack questions, users are encouraged to consult the following resources: