spack

how to use

spack repo add /path/to/repo
spack install nuisance3 #wait a while

Don't want spack to build root for you?

If you want to use an external copy of root instead of letting spack manage it, you can use the you-can-take-my-root-but-you-can-never-take-my-freedom.py script to put the currently-visible root environment as a non-buildable external into ~/.spack/packages.yaml