I tested same thing for OS user 'root' (/root), 'postgres' (/var/lib/pgsql ), and other two normal users who has home directory in /home.
But I got same error.
---- [ pgagent_96.log ]
WARNING: Couldn't create the primary connection (attempt 10): fe_sendauth: no password supplied ERROR: Stopping pgAgent: Couldn't establish the primary connection with the database server.
5. Checked my .pgpass file. ( .pgpass is in frank's home directory. /home/frank )
Frankly[1], this is probably your problem. pgAgent is most likely not running as user "frank". You need to identify what O/S user the application is running under and place the .pgpass file in that user's home directory.