Re: BUG #17821: Assertion failed in heap_update() due to heap pruning

On Mon, Mar 03, 2025 at 05:07:10PM -0500, Andres Freund wrote:
> On 2025-01-22 18:13:49 -0800, Noah Misch wrote:
> > Attached.  Outside of comments and tests, it's a simple 20-line patch.  Since
> > only two weeks will remain before release freeze, in the absence of review, I
> > would push this after 2025-01-25T16:00+0000.
> 
> I just fixed skink, the valgrind animal, so it runs not just the main
> regression tests but all tests with a valgrind-ified postgres.

Thanks.

> Unfortunately,
> the next run triggered a failure in the test added in this thread:
> 
> https://buildfarm.postgresql.org/cgi-bin/show_stage_log.pl?nm=skink&dt=2025-03-03%2019%3A52%3A38&stg=injection_points-check
> 
> diff -U3 /home/bf/bf-build/skink-master/HEAD/pgsql/src/test/modules/injection_points/expected/syscache-update-pruned.out /home/bf/bf-build/skink-master/HEAD/pgsql.build/testrun/injection_points/isolation/results/syscache-update-pruned.out
> --- /home/bf/bf-build/skink-master/HEAD/pgsql/src/test/modules/injection_points/expected/syscache-update-pruned.out	2025-01-25 19:30:50.005386842 +0000
> +++ /home/bf/bf-build/skink-master/HEAD/pgsql.build/testrun/injection_points/isolation/results/syscache-update-pruned.out	2025-03-03 21:08:02.025314915 +0000
> @@ -75,6 +75,7 @@
>  	SELECT FROM injection_points_wakeup('heap_update-before-pin');
>   <waiting ...>
>  step grant1: <... completed>
> +ERROR:  tuple concurrently deleted
>  step wakegrant4: <... completed>
>  step inspect4:
>  	SELECT relhastriggers, relhassubclass FROM pg_class
> @@ -82,6 +83,6 @@
> 
>  relhastriggers|relhassubclass
>  --------------+--------------
> -f             |f
> +t             |t
>  (1 row)

That isolation permutation tests an unfixed bug.  Here, it's giving a result
as though the bug were fixed.  The suite passed the next two skink runs.  I'd
tend to defer debugging exactly what went wrong until the project to fix the
bug under test.  I could delete the permutation, or I could leave it awhile to
see how high-probability this failure is.  I'm inclined to leave it until it
gets four failures, then delete the permutation.