os-shell postgre return no output

[winnerawan]

os-shell return no output, below the detail server

[19:16:41] [INFO] adjusting time delay to 1 second due to good response times
PostgreSQL 9.5.12 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609, 64-bit
web server operating system: Linux Ubuntu
web application technology: Nginx
back-end DBMS operating system: Linux Ubuntu
back-end DBMS: PostgreSQL
banner:    'PostgreSQL 9.5.12 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609, 64-bit'

[stamparm]

Not sure what to debug and/or discuss here. This is a plain example where you have to invest some time to find out what is going on. Also, you had an Issue template where you could fill in basics.