When running my Java app I get...
uki@.. $ java -jar ./build/libs/XYZ-1.0.jar
Vacuum 'gps_points' table...
org.postgresql.util.PSQLException: FATAL: password authentication failed for user "postgres"
FIX:
uki@.. $ psql -d polygons --user=postgres -c "ALTER USER Postgres WITH PASSWORD 'my_secret';"
ALTER ROLE