We started producing debug packages for the build system in bug 4414. However newer versions of rpm changed how these are generated, so we had to tweak things in bug 7162. Unfortunately we couldn't fix everything for this new rpm, so we're currently lacking build-id symlinks in the debuginfo packages. This can cause problems for tools such as gdb to find the proper binary.
We may need to re-evaluate how our rpms are built. It seems like using noarch and getting fully working debuginfo packages are not compatible concepts.
We don't really see a need for this. We started doing debug packages as a way to strip debug symbols because of their size, not because we really wanted to debug things.