inn-devel-2.2-8 does not install INN's include files.

inn-devel-1.7 in RH 5.2 installed dbz.h, inndcomm.h, and
libinn.h.  No .h files are installed by 2.2 RPM.  Include
files are required for INN-related software to compile.

For INN 2.2, the "suck" client requires the following files
to be installed from inn-2.2/include:

#include <configdata.h>
#include <clibrary.h>
#include <libinn.h>
#include <dbz.h>

At least these four files are required.  Other clients may
require additional files.