Hello
Thank you for report. Can you verify you using psql version 12beta2? You see message like this:
> ./psql
> psql (12beta2)
> Type "help" for help.
>
> postgres=#
For example "\d pg_stats" works for me in this case
Or something like:
> psql (11.4 (Debian 11.4-1.pgdg100+1), server 12beta2)
> WARNING: psql major version 11, server major version 12.
> Some psql features might not work.
> Type "help" for help.
>
> postgres=#
Older psql version should give such error, this is expected and we write warning about it.
regards, Sergei