yum broken; headers directory missing

[Andy Ross]

The "headers" directory has disappeared from the development trees.
Yum cannot update, and is dying with the following error:

Error getting file http://download.fedora.redhat.com/pub/fedora/linux/core/development/i386/headers/header.info
[Errno 4] IOError: HTTP Error 404: Not Found

I *do* notice a "headers" directory at the top level (alongside
the architecture directories).  Did something get misplaced?

Andy