[Dovecot] --enable-headers-install problem in 1.0.5

I am trying to get a SPEC file for an RPM to build a devel package. I have it working, except for one thing. 1.0.5 doesn't actually install the headers with that option to configure found in the subject.

It does create the directory, but it doesn't put the files there.

Timo, is this a known/unknown bug, or am I doing something stupid?

Thanks, Trever