Re: Sync scan & regression tests

Heikki Linnakangas <hlinnaka@iki.fi> writes:
> With shared_buffers='20MB', the tests passed. I'm going to change it
> back to 10MB now, so that we continue to cover that case.

So chipmunk is getting through the core tests now, but instead it
is failing in contrib/pg_visibility [1]:

diff -U3 /home/pgbfarm/buildroot/HEAD/pgsql.build/contrib/pg_visibility/expected/pg_visibility.out
/home/pgbfarm/buildroot/HEAD/pgsql.build/contrib/pg_visibility/results/pg_visibility.out
--- /home/pgbfarm/buildroot/HEAD/pgsql.build/contrib/pg_visibility/expected/pg_visibility.out    2022-10-08
19:00:15.905074105+0300 
+++ /home/pgbfarm/buildroot/HEAD/pgsql.build/contrib/pg_visibility/results/pg_visibility.out    2023-09-02
00:25:51.814148116+0300 
@@ -218,7 +218,8 @@
      0 | t           | t
      1 | t           | t
      2 | t           | t
-(3 rows)
+     3 | f           | f
+(4 rows)

 select * from pg_check_frozen('copyfreeze');
  t_ctid

I find this easily reproducible by setting shared_buffers=10MB.
But I'm confused about why, because the affected test case
dates to Tomas' commit 7db0cd214 of 2021-01-17, and chipmunk
passed many times after that.  Might be worth bisecting in
the interval where chipmunk wasn't reporting?

            regards, tom lane

[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=chipmunk&dt=2023-09-01%2015%3A15%3A56