When uninstalling libtool, following occurs:
(1/4) Removing libtool-2.4.6-2.16
..............................................................................................................................................................................................[done]
Additional rpm output:
install-info: No such file or directory for /usr/share/info/libtool.info.gz
warning: %postun(libtool-2.4.6-2.16.x86_64) scriptlet failed, exit status 1


It seems to be caused by:
%postun
%install_info_delete --info-dir=%{_infodir} %{_infodir}/libtool.info.gz

which was reintroduced to libtool with latest change:
on May  4 09:40:09 CEST 2015 - pth@suse.de

- Fix call of install_info.