> the changes you are requesting aren't really a bug

Your work in the Ubuntu community is noteworthy and commendable, but your comment evinces that you haven't been affected by the problem. Perhaps, then, you are not in the best position to make such an assessment. As the old saying goes, "One man's bug is another man's feature." 

It would be difficult to find a dependency that is more "bug-like" than this one. Incorrect dependencies are indeed a bug if they interfere with other packages or if they cause problems with updates. In this case, dragging in something as pernicious and insidious as avahi causes severe problems with network connectivity because avahi-daemon, avahi-autoipd, and libnss-mdns override configurations set up by the network administrator. The "disabling" of avahi-daemon in /etc/default/avahi-daemon is often cited as a potential solution, but that only disables part of avahi's interference with the network configuration. The pervasive changes to the networking stack, which are required to make the avahi family of packages work, end up being next to impossible to disable short of uninstalling the packages themselves. 

Simply removing the offensive packages does solve the networking problem, but the dependency issue prevents clean upgrades in the future. Because ubuntu-desktop depends on avahi-daemon, avahi-autoipd, and libnss-mdns, removing them requires removing ubuntu-destop as well. Removing ubuntu-desktop, in turn, causes upgrades not to perform as expected. (See the package description of ubuntu-desktop.) Thus, the impetus for this bug report. 

>require more discussion

There's nothing to be gained by discussion in the mailing lists. Avahi's functionality has already been argued about for two or three years now. Discussions on the mailing lists inevitably devolve to a stalemate between two competing use cases: If you have a small, ad-hoc network and understand avahi's untrustable nature, avahi can be a convenience. But if your network is large enough to require central administration, trust relationships among network clients, and/or stable IP addressing via DHCP server administration, avahi causes innumerable headaches. (If you haven't had the opportunity to implement avahi-laden Ubuntu desktops in an organizational environment, you have been spared much frustration.)

The server team had an extended conversation about avahi last November. Although the efficacy and advisability of avahi was hotly disputed, everyone seemed to agree that avahi should not be on a server, or for that matter, any system that is not behind a firewall. Eventually, we dropped the discussion and agreed that avahi is one of several reasons that the Ubuntu Server Edition should not ship with any of the currently configured desktop environments.

Although I am persuaded that reasonable minds can differ regarding the efficacy and utility of avahi.  Avahi, for those who understand its limitations and in the right use case, does what it's designed to do. Seen in that light, avahi can be considered an alternative protocol for ad hoc networking, in contrast to the standard and ubiquitous DHCP. Because the basic networking stack already includes DHCP, avahi is an overlay that is not essential to the basic functionality of the desktop. 

Whether or not one agrees with those of us who must work in organizational settings, the dependency level can and should be set in accordance with the meanings given to the various dependency levels. 



Happy Trails, 


Loye Young
Isaac & Young Computer Company
Laredo, Texas
http://www.iycc.biz