I tried adding a root password following the raspi.debian.net <http://raspi.debian.net/> page instructions and enabling root access via ssh, but it looks like to me that the script doesn’t work, or more likely I did something wrong. I created the sysconf.txt file with root_pw=password in both /boot/firmware on the second partition and on the first partition since I didn’t know what /boot folder to user (but I guess it was the one on the second partition).
I ended up adding an ssh public on /root/.ssh/authorized_keys and logged in this way. By the way on boot ifupdown tries to start eth0 as instructed by /etc/network/interfaces.d/eth0 but fails because there are two iptables-restore lines, but the package is not even installed. I removed the two lines and everything works fine. — fl4co
