Re: pg_dump error attempting to upgrade from PostgreSQL 10 to PostgreSQL 12

On Sat, Nov 7, 2020 at 1:10 PM Tomas Vondra
<tomas.vondra@enterprisedb.com> wrote:
> On Thu, 5 Nov 2020 21:19:17 +0000
> "Burgess, Freddie" <Freddie.Burgess@maxar.com> wrote:
> > BACKUP: pg_dump -U postgres -d <database> > sherlock.dmp  <- From the
> > pg10 instance RESTORE: psql -U postgres -d <database> -1 -f
> > sherlock.dmp <- On the pg12 instance
> >
> > Postgres Log:
> >
> > free(): invalid pointer
> > free(): invalid pointer
> > 2020-11-05 14:07:33.784 EST [26] LOG:  background worker "parallel
> > worker" (PID 150) was terminated by signal 6: Aborted 2020-11-05

> It'd be interesting to know what is doing the crashing parallel worker.
> Considering it's a background worker, the easiest way is probably
> enabling core dumps and inspecting them with gdb. Make sure you have
> debug symbols installed and send us the backtrace.

I guess that would have to be a parallel index build.  The OP could
try setting max_parallel_mainentance_workers = 0 to see if that's a
useful workaround, until we can track the problem (double free?) down
and fix it, or maybe that would reveal that the same crash can also
happen in a regular backend.