samba - Sep 2011 - samba 3.6.0 compile error --enable-external-libtdb=yes (works for samba-3.5.11)

Hello

I'm trying to compile samba-3.6.0 on a RHEL6 server (relevant options
below):

    --with-libtalloc=no \
    --enable-external-libtalloc=yes \
    --with-libtdb=no
    --enable-external-libtdb=yes

This does not work, I get an error "Unable to find libtdb".  However:

libtdb-devel-1.2.1-3.el6.i686
libtdb-1.2.1-3.el6.i686

have been installed.

This works fine when I try to build samba-3.5.11 on the same machine.

What's has changed?
I could find that in Fedora Rawhide they have disabled this option in the spec
file but without specifying a reason:
http://permalink.gmane.org/gmane.network.samba.internals/55452


Kind regards

Werner