The doc seems to say nothing that one needs to be root in order to build
the kernel but the %install phase fails on mknod ./dev/socksys c 30 0
with 'permission denied' message.
If this is a feature (i.e. you are positive there is no way to build kernel
as non-root) I would not mind if it was mentioned somewhere (rpm doc?).
I am reporting this bug as well. I'd like to suggest the following compromise
for the mknod problem, referring back to bug 10500. Invoke mknod as follows:
su root -c "mknod ./dev/socksys c 30 0; mknod ..."
This will result in no functional change when the RPM is built as root. su will
be a no-op in that situation. But this will also allow the RPMs to be rebuilt
interactively as non-root, simply by entering the password once during the build
process. This works well, I've tested it.
The current RawHide/Beta kernel packages build as non-root.