pg_lsclusters is not part of core Postgres, and neither is this --cluster option you mention. I'm vaguely aware that some packager (Debian I think) has added an overlay of that sort; but you'd need to consult the package-level documentation not the community docs in order to find out more.
Sorry, my fault, it's Debian/Ubuntu. Actually they must have added the --cluster option to the PG programs through source code patches...
So, forget about the packager. With core PostgreSQL tools it is possible to have more than one cluster. How do you specify what cluster to connect to with psql or pg_dump? Do I have to specify the cluster's corresponding Unix domain socket directory via the --host option?
Regards, Carsten
