Comment # 1 on bug 1207804 from Wilms

Apparently this was only an issue with GNOME_Factory:

zypper lr -u

#  | Alias                                | Name                               
           | Enabled   | GPG Check       | Refresh        | URI
---+--------------------------------------+------------------------------------------------+-----------+-----------------+----------------+----------------------------------------------------------------------------------
 1 | GNOME_Factory                        | Development branch of GNOME
(openSUSE_Factory) | Yes        | (r ) Yes         | No           |
https://download.opensuse.org/repositories/GNOME:/Factory/openSUSE_Factory/