BUG #18154: Corrupt DB: pg_dump segfaults or returns empty

The following bug has been logged on the website:

Bug reference: 18154
Logged by: Franz-Josef Färber
Email address: franz-josef(dot)faerber(at)stmuk(dot)bayern(dot)de
PostgreSQL version: 15.4
Operating system: Ubuntu, Debian, Windows
Description:

Hello,

somehow I had managed to corrupt my database (postgres 15.4). At least I can
say I could still access many database objects, but
* VACCUM FULL fails with error "uncommitted xmin 4518 from before xid cutoff
7279 needs to be frozen"
* Further investigating, at least the table pg_statistic seems to be
corrupt, I cannot query it with SELECT.
* The tips in https://gist.github.com/supix/80f9a6111dc954cf38ee99b9dedf187a
didn't work.

But this is is not the reason I file this bug report. The reason is the
behaviour of pg_dump.

pg_dump 15.4 on Ubuntu segfaults. Shouldn't it at least print a meaningful
error message and exit cleanly?

By the way, pg_dump 16 on Windows seems to exit cleanly, dumping exactly
nothing onto stdout.

These behaviours were observed using a command line like "psql --host=myhost
--username=myuser mydb".

Regards,
fjf2002