The most appropriate kernel-devel package that shows up in yum is
2.6.15-1.2041_FC5-i686 but the "build" symlink in
/lib/modules/2.6.15-1.2041_FC5smp points to
../../../usr/src/kernels/2.6.15-1.2041_FC5-smp-i686
which isn't installed by the kernel-devel package

I don't know if this is an actual bug or me not finding the right
bit of documentation. Perhaps the sources are all the same but
the .config needs a slight tweak? Even if this is ESTOOPIDUSER,
it would be nice if the rpms just did the right magic so the
issue never came up.