We realized today [1] that it's been some time since the buildfarm had any debug_discard_caches (nee CLOBBER_CACHE_ALWAYS) coverage. Sure enough, as soon as Tomas turned that back on, kaboom [2]. The test_oat_hooks test is failing --- it's not crashing, but it's emitting more NOTICE lines than the expected output includes, evidently as a result of the hooks getting invoked extra times during cache reloads. I can reproduce that here.
Maybe it was a poor design that these hooks were placed someplace that's sensitive to that. I dunno. The only short-term solution I can think of is to force debug_discard_caches to 0 within that test script, which is annoying but feasible (since that module only exists in v15+). Thoughts, other proposals? regards, tom lane [1] https://www.postgresql.org/message-id/6b52e783-1b32-e723-4311-0e433a5a5a75%40enterprisedb.com [2] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=avocet&dt=2022-11-18%2016%3A01%3A43