Building RPMs cleanly

I recently found this script recently to build a solr rpm and I love how it simply solves so many problems with RPM packaging with a few defines. Here's my slightly modified version for building an apache package, which leaves the SOURCES directory untouched and keeps a log of the build so you can go back and review it later:

#!/bin/sh -x
rm -rf BUILD RPMS SRPMS tmp || true
mkdir -p BUILD RPMS SRPMS tmp

rpmbuild -bb --define="_topdir $PWD" --define="_tmppath $PWD/tmp" apache.spec 2>&1 | tee apache-build.txt