Here's my log:

git ls-files | tar --files-from /proc/self/fd/0 -czf "ovirt-engine-3.3.0_master.tar.gz" ovirt-engine.spec

You can use rpmbuild -tb ovirt-engine-3.3.0_master.tar.gz to produce rpms

rm -rf "/home/demo/gittest/ovirt-engine/tmp.rpmbuild"
mkdir -p "/home/demo/gittest/ovirt-engine/tmp.rpmbuild"/{SPECS,RPMS,SRPMS,SOURCES,BUILD,BUILDROOT}
mkdir -p "output"
rpmbuild -ts --define="_topdir /home/demo/gittest/ovirt-engine/tmp.rpmbuild" "ovirt-engine-3.3.0_master.tar.gz"
Wrote: /home/demo/gittest/ovirt-engine/tmp.rpmbuild/SRPMS/ovirt-engine-3.3.0-0.2.master.20130621014614.fc18.src.rpm
mv "/home/demo/gittest/ovirt-engine/tmp.rpmbuild/SRPMS"/*.rpm "output"
rm -rf "/home/demo/gittest/ovirt-engine/tmp.rpmbuild"

srpm is ready at output

rm -rf "/home/demo/gittest/ovirt-engine/tmp.rpmbuild"
mkdir -p "/home/demo/gittest/ovirt-engine/tmp.rpmbuild"/{SPECS,RPMS,SRPMS,SOURCES,BUILD,BUILDROOT}
mkdir -p "output"
rpmbuild --define="_topdir /home/demo/gittest/ovirt-engine/tmp.rpmbuild"  --rebuild "output/ovirt-engine-3.3.0*.src.rpm"
error: cannot open output/ovirt-engine-3.3.0*.src.rpm: No such file or directory
make: *** [rpm] Error 1