[R-sig-Debian] "Failed-to-restart-avahi-dnsconfd-service" error SOLVED (I think!).

[Rolf Turner]

For the record, I'd like to describe the steps I took to solve the 
problem.  As David pointed out, this really has nothing to do with R, 
but it's *just possible* that someone might find it handy.

To those who are not interested (everybody?) I apologise.  Please just 
press the <delete> key.

The problem was that when I did:

    sudo apt-get upgrade

I got an error message to the effect:

> Setting up avahi-dnsconfd (0.7-3.1ubuntu1.1) ...
> Failed to restart avahi-dnsconfd.service: Unit avahi-daemon.service is masked.
> invoke-rc.d: initscript avahi-dnsconfd, action "restart" failed.
> ● avahi-dnsconfd.service - Avahi DNS Configuration Daemon
>    Loaded: loaded (/lib/systemd/system/avahi-dnsconfd.service; enabled; vendor preset: enabled)
>    Active: inactive (dead) 

I had previously Googled around about the avahi business and had found 
nothing useful, but when I tried again I found:

     https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=768620

which contained the lines:

> Dear Maintainer,
> 
> to resolve this mess manually these steps are sufficient:
> 
> systemctl disable avahi-daemon
> apt-get --reinstall install avahi-daemon
> systemctl enable avahi-daemon
> 
> after that i can reinstall the packages without any problems

I then tried

     sudo systemctl disable avahi-daemon

and got (amongst other things) the message

> /etc/systemd/system/avahi-daemon.service is masked, ignoring.

More Googling about the "masked" business seemed to reveal that masking 
is effected by making a symbolic link from the file in question to 
/dev/null, and if this is the case then unmasking can be accomplished by 
removing the symbolic link.

I did

     cd /etc/systemd/system
     ls -l avahi-daemon.service

and indeed got

> lrwxrwxrwx 1 root root 9 Aug 20 16:05 avahi-daemon.service -> /dev/null

So I then did:

     sudo rm avahi-daemon.service
     sudo systemctl disable avahi-daemon

and this time it seemed to run OK.

I then tried "sudo apt-get upgrade" again.  The first time I got the 
slightly ominous:

> Setting up avahi-dnsconfd (0.7-3.1ubuntu1.1) ...
> W: APT had planned for dpkg to do more than it reported back (0 vs 4).
>    Affected packages: avahi-dnsconfd:amd64

But a second iteration seemed to produce a clean bill of health.

I then tried "sudo apt-get install r-base" one more time,
and encountered a further but entirely separate problem (to which I have 
alluded before) but which is really a separate issue.  And really *is* 
an R (or R-Sig-Debian) problem.

But I think that is best dealt with in a new thread.

cheers,

Rolf Turner

-- 
Honorary Research Fellow
Department of Statistics
University of Auckland
Phone: +64-9-373-7599 ext. 88276