[BUGS] PostgreSQL 10 - data directory location

Show commands return incorrect data directory location:

SHOW data_directory; returns /var/lib/postrgesql/data

SHOW config_file; returns /var/lib/postgresql/data/postgresql.conf

However, the data directory is completely empty.

Also when I run oid2name, it returns the following error:

"Could not connect to server: No such file or directory. Is the server running locally and accepting connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"". It may be related to the first part of the question.