GitLab Runners cleaning campaign ongoing (ETA 2nd October 2023). Check https://cern.ch/otg0078219 for further information.
This change set syncs Rivet_i back with 21.6 and fix all the compiler issues previously seen. With this MR it should be fine to include it back into the Nightly builds.
FYI @zmarshal @ewelina @jchapman @lcorpe @dkar