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


https://man7.org/linux/man-pages/man1/hostnamectl.1.html
yep, I used that command to modify the hostname, rather than edit /etc/hostname directly