Symptom will obviously be undefined symbols when doing depmod. Took me quite a while before the cause dawned on me :-D
Heads up for anyone trying this. Filesystem layout for kernel modules
has changed, I ended up with left-over modules from 9999 when
downgrading, needs manual clean-up. Would maybe be a good idea to update
the ebuilds for the non-git ebuilds to either the new layout or to clean
up the version-9999 files in postinst.
