From the whole mess of kernel packages --
only ksymoops won't built as non-root user.
It fails on install stage -- called from .spec as
make install -C ksymoops-%{ksymoopsver}
INSTALL_PREFIX=$RPM_BUILD_ROOT/usr.

In Makefile for it, target install:
  $(INSTALL) -d -o root -g root $(INSTALL_PREFIX)/bin
install: /var/tmp/rpm.../bin: Operation not permitted

Ksymoops has only two files (exe&man), so it will be trivial
to install it from .spec file directly.

That is very annoying to see that rpm build failed on the last
stage after some hours of compiling...