Comment 38 for bug 497299

Some thoughts about this issue.

1) When no /etc/network/interfaces is available, It seems that upstart is waiting for lo to be brought up before starting services; however network manager, responsible for bringing up lo is not started by upstart; creating the circular dependency.
2) When /etc/network/interfaces is available, some other program, not under upstart control, brings lo up, and everything seems to work.

If this is true, a possible solution to the problem is to let some processes (e.g. NetworkManager) be started by upstart regardless of lo status.

Still I'm not sure 100% about what I'm saying, because in case 1), when the user logs in, Network manager seems to be actually running (or, better, network is properly working, so I assume it's NetworkManager running). So who started netwrokmanager in case 1) ?