I ran 2.9 and got that error, then I updated to 3.0 and got the same. My Machine is running MAAS alongside juju.
novski@maas:~$ juju bootstrap localhost juju-ctrl ERROR ensuring default bridge config: The DNS and DHCP service exited prematurely: Process exited with non-zero value 2 ("dnsmasq: failed to create listening socket for 10.176.40.1: Address already in use")
While the IP constantly changes inside the 10.0.0.0/8. Shouldn’t there be a Port behind the IP?