serge@serge:/ArtistsRating$ psql artistsrating < /ArtistsRating_db_2018_06_18.sql
psql: FATAL:  role "serge" does not exist

PostgreSQL 10.4 (Ubuntu 10.4-0ubuntu0.18.04) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 7.3.0-16ubuntu3) 7.3.0, 64-bit

$ sudo -u postgres psql
psql (10.4 (Ubuntu 10.4-0ubuntu0.18.04))
Type "help" for help.

postgres=# \dg
                                   List of roles
 Role name |                         Attributes                         | Member of 
-----------+------------------------------------------------------------+-----------
 postgres  | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

CREATE ROLE serge WITH SUPERUSER;
CREATE ROLE

serge@serge:/mnt/_work_sdb8/wwwroot/lar/TasksBs41$ psql artistsrating < /_wwwroot/lar/ArtistsRating/__SQL/DUMPS/ArtistsRating_db_2018_06_18.sql
psql: FATAL:  role "serge" is not permitted to log in