When doing a 'make mrproper' with CONFIG_MODVERSIONS set the following is deleted...
rm -f /usr/src/linux/include/linux/modversions.h
rm -f /usr/src/linux/include/linux/modules/*
Now when a nonversioned kernel is made it will fail with
make[1]: Entering directory `/usr/src/linux/kernel'
make[1]: *** No rule to make target `ksyms.ver'. Stop.
ksyms.ver is a link to include/linux/modules/ksyms.ver and this is only created in a versioned
kernel. I don't think that ksyms.ver is used in a non-versioned kernel and the problem is just
in the Makefile rules.
This is with 1.3.10 (and others) and GNU make 3.71.
-- INSSOMNIAK