Comment # 4 on bug 1060560 from Tony Su

Affects at least machines with the following kernels installed and their
corresponging kernel-devel and kernel-default-devel packages

4.4.87-25-default
4.4.85-22-default

This is something new, that for whatever reason had not been seen for more than
15 years (AFAIK) but suddenly happened this past month.

In case I overlook in the terminology I use here, it should be noted that
everywhere I describe a "default kernel" or "default kernel version" I am not
referring to the kernel build, everywhere I am referring only to a default
behavior, selection or version.

This kernel and kernel header packages mis-match manifests itself arbitrarily
in two ways, where the kernel might be newer than the headers, or the headers
might be newer than the kernel.

I've described at the end of the first post the 2 workarounds which should
work.

Workaround 1
When the kernel is newer than the headers, because header packages both old and
new exist, removing the wrong (old) headers package manually <can> force
matching, but I've very recently been in contact with another person who has
been discussing their same problem with me that this workaround did not work
for him.

Workaround 2
When the kernel is older than the headers, this is because for some reason the
Grub2 default does not automatically select the newest installed kernel. It is
then possible to force the newest kernel by selecting the Advanced option and
explicitly choosing the newest kernel. It is then also possible to make this
explicit selection default by modifying the Grub2 boot configuration by using
the YaST Boot module, but I fear this can only be a temporary solution and will
prevent a future kernel upgrade(so has to be undone eventually).

I find it odd that both these similar but different issues appeared at exactly
the same time.
Personally, I wouldn't know exactly where to look for possible causes but of
course the following are reasonable starting points. I'd be willing to look at
the relevant code myself but currently have no idea how to navigate to where
the problems might exist.

- Where is, and what governs how the OS selects the appropriate files from the
kernel-devel and kernel-default-devel packages?

- Unless the kernel and kernel header packages have somehow changed, it's
likely that the code that selects the kernel header files has changed in the
past month or two.

- The code specifically in grub2 that specifies the default kernel version is
likely suspect.

I understand that this is one of those extremely difficult problems to
troubleshoot because this does not seem to be consistent both because this is
not appearing in all machines and even when it happens, either the kernel or
the kernel headers may be newer than the other.

But, from my software experience (as limited as it might be), this usually has
pointed to a logic problem, not a simple statement problem.