Comment (by Roland Haas):

Pontially this could be solved by collapsin use_psync, psync_error and psync_only into a single KEYWORD parameter with like so:

KEYWORD presync_level "how strongly to check data access"
{
  "no"    :: "disable all runtime checks"
  "check" :: "check allowed access and data correctness at runtime"
  "sync"  :: "automatically synchronize when needed"
  "only"  :: "disallow old-style boundary conditions and explicit synchronization"
} "no"

where “check” would be something like psync_error=yes and use_psync=no (so one needs to check that this actually works), while “sync” has them both on and “onyl” adds psync_only.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2377/cactus-psync_error-yes-without-cactus