Apologies, I don't have the exact errors messages from the installer. I had a few failed install attempts, each time fixing issues and progressing further. At one point however the installer would fail to drop the existing users and databases within the postgresql database. 3 databases appear to get created, $db_name (cloudify_db), stage and composer, all get associated with the cloudify user that's created. The installer however only drops $db_name (cloudify_db) which then means the subsequent 'DROP USER IF EXISTS $user:' command will fail as the user cannot be dropped with databases associated to it. This is fixable by also dropped the stage and composer databases before attempting the drop user command (or a different way of handling, removing the user from those databases first for example).
Line 26:27 in '/opt/cfy/cloudify-manager-blueprints/components/postgresql/config/create_default_db.sh'