As a workaround, type asdasdasd... while systemd is starting NetworkManager. It helps shorten the wait :)
Also I tried installing haveged, it didn't help. -- Alexander E. Patrakov
I have added the "strace -tT" to the unit file. Result: the time is
spent in a blocking "getrandom" call. In other words, NetworkManager is
started before the system's non-blocking entropy pool is initialized.
