Comment (by Roland Haas):

Vesta has been retired on 2019-12-31: https://www.alcf.anl.gov/support-center/miracetusvesta/decommissioning-mira so it no longer blocks the ET from requiring all of C++11. Th e LONI machines are still around but at this point may well have been updated. The retired Perimeter Institute machines have already been removed.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2207/support-all-of-c-11-in-cactus-or-the