Comment # 23 on bug 1037700 from Michael Andres

Thanks. Actually it is no bug, but there's something we can improve...

'zypper update' does a 'best effort' approach. It will update packages as far
as possible, but it will never raise any conflict. If a newer version can not
be installed for some reason, the package won't be updated. This way you can
use 'zypper up' unattended (e.g. in cron scripts).

Usually multiple kernel versions can be installed in parallel.
kernel-default-4.10.13-1.4 however explicitly obsoletes versions 4.10.13-1.1,
4.10.13-1.2 and 4.10.13-1.3. Thus installing 4.10.13-1.4 would require removing
the installed 4.10.12-1.2. Due to this conflict 'zypper update' skips
4.10.13-1.4. 
I don't know why, but the kernel maintainers explicitly prevent those versions
from being installed together.


'zypper dup' is more aggressive, that's why it will 4.10.12-1.2 to enforce
4.10.13-1.4. AFAIK Tumbleweeed even recommends using 'zypper dup
--no-allow-vendor-change' rather than 'zypper up'.


We're now thinking about introducing a force-best option for 'zypper update',
which will force the resolver to use the best version, even if it needs to
raise conflicts. With such an option zyyper would ask whether it's ok to remove
4.10.12-1.2 in order to install 4.10.13-1.4.