Comment # 8 on bug 1180592 from Stefan Hundhammer

So, does your system have any zypper locks?

This is the libzypp / zypper equivalent of the YaST package selector "taboo"
and "protected" package states. "taboo" sets a lock on a not-installed package,
i.e. it will never be installed. "protected" sets a lock on an installed
package, i.e. it will remain on the system in the current version.

In some pathological cases, any of those can trigger a cascade of dependencies
that may ultimately lead to the dependency resolver choosing to remove a
package to satisfy all package dependencies.

That can also happen in other difficult package dependency problems; the sort
where the dependency resolver asks you to choose one from a number of available
options.


We do have package dependencies on our YaST and libyui packages, of course, but
they are set up in a way that allows users to get rid of optional parts if
desired: YaST needs some kind of user interface (UI). We have two officially
supported ones (libyui-qt and libyui-ncurses) and one community-supported
(libyui-gtk). Any of them is sufficient to satisfy the dependency. Most average
users will prefer to have libyui-qt, but some users actually don't want
anything Qt on their systems, so only having libyui-ncurses is a viable option
as well.

To get libyui-qt installed in standard installations, that package is part of
software patterns that involve graphical desktops; but that works with a soft
dependency, an RPM "recommends". That means if possible, it is installed, but
if for some reason this doesn't work, it's okay to not install it.

So for example if you choose to install Qt 6 from some other repository, and
that Qt 6 hypothetically conflicts with the Qt 5 that is required by our
libyui-qt, you won't get libyui-qt because Qt 5 cannot be installed because you
prefer Qt 6. You get the idea. And there may be any number of more dependency
indirections leading to even more complicated scenarios.

In any case, you will still have libyui-ncurses, so you can always open a shell
window and run "/sbin/yast repositories". It's not graphical, but it works.


So, without further information, we can only speculate what exactly happened in
your scenario. So far, we haven't heard of any similar cases, so AFAICS this is
not a general problem affecting all TW users.