Re: Sync scan & regression tests

Heikki Linnakangas <hlinnaka(at)iki(dot)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