hehe, so … if you ever change the hostname of a Linux machine, you really really ought to double-check /etc/hosts to make the same hostname change there
it’s surprising just how much will break if a machine’s own hostname isn’t resolvable to a 127.x.x.x address :P
it modifies /etc/hostname for you, but doesn’t seem to touch /etc/hosts
i still prefer hostnamectl, but i’m now unsure of what benefit it offers over editing /etc/hostname directly