Comment # 4 on bug 1205456 from Martin Wilck

Thanks. Summing up,

 1 All zypp patches conflict with all package versions younger than the
packages contained in them
 2 There is overlap between the packagelists between OpenSUSE SLE imports and
Packman

=> "zypper patch" will never work reliably on systems that enable 3rd party
repositiories.

 3 gpk-update-viewer builds upon zypper's patch functionality

=> Forget about gpk-update-viewer on Leap

Together with

 4 packman is necessary for a lot users to perform every-day tasks and

 5 gpk-update-viewer is a prominent part of the GNOME desktop and is (afaik)
the only way in which ordinary users can install updates without becoming root

this has quite a negative impact on the overall user experience. The "this is
how it is" kind of answers in this bug make me realize that this isn't going to
change.

I suppose it's a WONTFIX then. A bit sad, but whatever.