Failed to start D-Bus System Message Bus

[fijam]

I soldered UART to see what's going on.

systemd starts correctly but at some point fails to start D-Bus, which makes User Login Management fail.

A snippet from the logs:

[  OK  ] Started D-Bus System Message Bus.
[  OK  ] Started D-Bus System Message Bus.
[  193.561713] systemd[1]: Failed to start D-Bus System Message Bus.
[FAILED] Failed to start D-Bus System Message Bus.
See 'systemctl status dbus.service' for details.
[     *] A start job is running for User Login Management (5s / 1min 30s)

This loops forever.