HPSF Conference 2025

Spack makes it easy to install dependencies for our software on multiple HPC platforms. However, there is little guidance on how to structure Spack environments for larger projects, share common Spack installations with code teams and utilize them in an effective way for continuous integration and development.

This presentation will share some of the lessons learned from deploying chained Spack installations for multiple code teams at LANL on various HPC platforms both on site and on other Tri-Lab systems, how to structure such deployments for reusability and upgradability, and make them deployable even on air-gapped systems. It will also show how we utilize Spack's build facilities to drive CMake-based projects on GitLab for continuous integration, without having to replicate build configuration logic in GitLab files, while giving developers an easy-to-follow workflow for recreating CI runs in various configurations.