How completely migrate from one supabase project to another (self hosted)

psql \                                                                    ─╯
  --single-transaction \
  --variable ON_ERROR_STOP=1 \
  --file roles.sql \
  --dbname "postgres://admin:password@myhost:port/db"

SET
SET
SET
psql:roles.sql:7: ERROR:  role "supabase_realtime_admin" already exists