Reduce test load of the spack CI build
The Spack CI build takes 2 hours. Is there anything we can do to reduce its load on the machines (though it appears to only be eligible for dovim
based on its tags)? Compile caching (though we'd want stable build paths for sccache to be really effective)? Can we make a Spack binary cache to reduce time spent building dependencies? It looks like there is an attempt to use a binary cache, but is that actually being used…2 hours seems like a long time? Or are we spending all our time in compressing/extracting that cache? I think there's a way to disable compression for the cache.
Cc: @omar-padron @tjcorona @utkarsh.ayachit @christos.tsolakis