[gentoo-user] Module and kernel woes after two "emerge -DuNe @world"s

[Grant Taylor]

I'm having problems with newly compiled modules (zfs (et al.) and vbox 
(et al.)) and kernel after doing two "emerge -DuNe @world"s.

Everything worked fine after rebooting after the first "emerge -DuNe 
@world".  So, I did another "emerge -DuNe @world".  (This harks back to 
the old stage 1 -> stage 2 -> stage 3 methodology that I cut my teeth 
on.  Create the new tool, use said tool to recreate the tool.)

After the reboot after this second "emerge -DuNe @world" is when my ZFS 
pool became inaccessible.

Aside:  I migrated from ZFS 0.7.999 to 0.8 as part of the first emerge. 
This worked fine.

I have since found out that I can't load vbox* modules, nor can I boot a 
kernel that I can successfully build.

The modules fail with the following error:

    modprobe: ERROR: could not insert '<module name>': Exec format error.

Dmesg reports the following associated error:

    [ <seconds since boot>] module: <module name>: Unknown rela 
relocation: 4

My searches online have made me think that this /might/ be a problem 
with newer binutils.  But I'm not sure.

So, I figured that I'd ask for some help / input before I do something 
drastic that I might regret, like making things worse, or painting 
myself into a corner that I can't back out of.

Aside:  I have regained access to my ZFS pool by restoring the ZFS 
contents of the /lib/modules/<version>/extra directory.