Estou executando o Debian 9.4. hostname funciona.
$ sudo strace -f hostnamectl
...snipped...
connect(3, {sa_family=AF_UNIX, sun_path="/var/run/dbus/system_bus_socket"}, 33) = -1 ENOENT (No such file or directory)
...
Failed to create bus...
07.09.2018 / 22:21