Forgive me if I'm not quite so sure, because this is the second time I've had an undiagnosable problem where systemd appeared to be waiting for something to start that was already started.
On my home system I had to roll back systemd altogether because it would hang for many minutes on /home and never get it mounted, but once logging in as root, fsck /home; mount /home worked the first time. This was undiagnosable and the system was effectively nonfunctional, so I had to roll it back immediately. Thankfully jesse's sysvinit package was still in apt's cache.
