[sigc] spec file and include path name

[Carl Nygard <cjnygard verizon net>]

I just downloaded 2.10, and I'm seeing a discrepancy between make
install and what the spec file is expecting.

lib version is 2.10
make install  tries to put includes in:
  test -z "/usr/local/include/libxml++-2.6/libxml++/parsers" || mkdir -p -- "/usr/local/include/libxml++-2.6/libxml++/parsers"
spec file is:
%files devel
%defattr(-,root,root)
/usr/include/libxml++-2.8
/usr/lib/*.a
/usr/lib/*.la
/usr/lib/pkgconfig/libxml++-2.8.pc

rpmbuild errors:

RPM build errors:
    File not found: /var/tmp/libxml++-root/usr/include/libxml++-2.8
    File not found: /var/tmp/libxml++-root/usr/lib/pkgconfig/libxml++-2.8.pc


At first I thought s/2.8/2.10/ in the specfile would work, but the
makefile using 2.6 makes me want to ask what's going on.

Guidance?