This is for the search engines. Installing Pi-Hole on an Ubuntu 18.10 system it wouldn’t start the DNS server. Looking at “service pi-hole status” I see this error:
May 31 15:00:05 gvl pihole-FTL: dnsmasq: cannot access /etc/dnsmasq.d/lxd: No such file or directory
For once Googling the error didn’t get me anywhere useful. I finally looked and found this symlink:
# ll /etc/dnsmasq.d/lxd
lrwxrwxrwx 1 root root 28 Apr 26 2018 lxd -> /etc/dnsmasq.d-available/lxd
However the entire directory /etc/dnsmasq.d-available/ doesn’t exist. So it’s a dangling symlink. Apparently dnsmasq.d refuses to start if it finds one of those, doesn’t just skip it. Removing that dangling symlink fixed the problem and now Pi-Hole starts.
No idea where the file came in. I tinkered with LXD on this machine in the past, maybe that’s a remnant of something I installed and then removed.