When attempting to build a package whose source contains symlinks, chgrp returns -1. The solution appears to be changing the macro: %_fixgroup [ `%{__id} -u` = '0' ] && %{__chgrp} -Rf root to; %_fixgroup [ `%{__id} -u` = '0' ] && %{__chgrp} -Rhf root in /usr/lib/rpm/macros
Fixed in (as yet unreleased) rpm-3.0.3. Thanks for the patch.