Anton Alkin

@davidrohr outdated system headers on slc7 seem to be the issue. Do we still need slc7 at all?

@ktf I thought for aliphysics it was a slightly different ROOT, with some patches? It is also possible to just fix arrow 14 in defaults-ali, since it is not used...

Why not explicitly disable it like in defaults-generators?

@ktf ROOT has arrow as an explicit dependency, can it override the defaults?

Other than "breaking" the current generalization, the code seems to do what is expected. I thinks this was tested long time ago and the effect on the AOD size was...