FAIL-LOUD, not fail-safe. A connection set to 'PerConnection' that has entity maps but no
per-connection catalog rows has not been backfilled, and answering from the shared catalog would
be indistinguishable from success: the sync would run, on a different set of objects, and report
nothing wrong. So it refuses, and the message names the connection, what it found, and the way
out.
The "has entity maps" part matters. A brand-new connection legitimately has neither maps nor
catalog rows — that is the state right before its first discovery, not a missing backfill — so
requiring rows there would refuse every new connector on the very flag that is supposed to be
safe to turn on.
The writer for this connection's catalog.
FAIL-LOUD, not fail-safe. A connection set to 'PerConnection' that has entity maps but no per-connection catalog rows has not been backfilled, and answering from the shared catalog would be indistinguishable from success: the sync would run, on a different set of objects, and report nothing wrong. So it refuses, and the message names the connection, what it found, and the way out.
The "has entity maps" part matters. A brand-new connection legitimately has neither maps nor catalog rows — that is the state right before its first discovery, not a missing backfill — so requiring rows there would refuse every new connector on the very flag that is supposed to be safe to turn on.