Using CVMFS with Spack at the FCC experiment

<!--HTML-->In preparation for the post-LHC era, the Future Circular Collider (FCC) Collaboration is undertaking design studies for multiple accelerator projects with emphasis on proton-proton and electron-positron high-energy frontier machines. From the beginning of the collaboration, the development of a software stack with common and interchangeable packages plays an important role in simulation, reconstruction or analysis studies. Similarly to the existing LHC experiments, these packages need to be built and deployed for different platforms and compilers. For these tasks FCC relies on Spack, a new package manager tool recently adopted by other experiments inside the High-Energy Physics (HEP) community. Despite its warm adoption, the integration of Spack with CVMFS for software distribution, while already possible, exposes some limitations. This talk provides an overview of these difficulties in the context of the FCC Software.