But I keep getting:

PostgreSQL is not available from calendarserver.org; trying upstream source.
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: ftp5.us.postgresql.org

I dont get the same issue on Mac OS (development laptop)