Comment 31 for bug 499361

Mathieu, you are correct, upstart makes it hard to know what's hanging since it's happening in parrallel in a non deterministic fashion, and it's not like I can run ps at that time.

I originally filed this against upstart, because quite franlky upstart does not make it easy to see what the problem is.
I however think the problem is with the network-manager init script. I think when I had
auto eth0
iface eth0 inet dhcp

It would sometimes bring try to bring up eth0 when it wasn't plugged in, and hang.
Note that there are 5 pictures:

boot with --debug
http://launchpadlibrarian.net/37077999/100_upstart_picts.jpg
http://launchpadlibrarian.net/37078016/101_upstart_picts.jpg

boot without --debug
http://launchpadlibrarian.net/37095414/StallPict1a.jpg
http://launchpadlibrarian.net/37095417/StallPict1b.jpg

boot that happened not to hang:
http://launchpadlibrarian.net/37095427/NonStall.jpg

I very seldom boot my laptop, especially now that it randomly does not complete booting, and honestly I can't tell for sure which process hangs upstart but it looks like it's network-manager