vp-build/common/hooks/pre-pkg/01-xdelta_repolist.sh

# this hook marks files which are about to change for generating vcdiffs

hook() {
	type -P xdelta3 > /dev/null || return 0;

	# create links to preserve old versions of repodata
	find $XBPS_REPOSITORY -name '*-repodata' | \
		while read; do
			ln "${REPLY}" "${REPLY}.genVcdiff"
		done
}