On Monday, April 23, 2018, PG Bug reporting form <noreply(at)postgresql(dot)org>
wrote:
>
> # Not expected, database "jibberish" does not exist:
> $ pg_isready -d jibberish
> /run/media/jthomas/BackupOne/development/snowdrift/.postgres-work:5432 -
> accepting connections
>
The notes section of the docs for the command cover this behavior. It is
not a bug, the utility answers whether the server will accept connections
generally, not that a specific connection string and credentials are valid.
David J.