The current srpm for VFlib2 has a bug in the specfile. The line... find $RPM_BUILD_DIR -name CVS -type d | sort | xargs rm -fr is too broad and searches all directories existing in /usr/src/redhat/BUILD rather than just the ones related to this srpm. This can be quite painful if you have a lot of directories left in your RPM_BUILD_DIR.
I fixed it with VFlib2-2.25.1-11.