upstream_version = $$(printf '%s' '$(OPK_SOURCE_VERSION_UPSTREAM)' | \
	sed 's/\./-/g')
upstream_url_base = https://github.com/lm-sensors/lm-sensors
upstream_url = $(upstream_url_base)/archive/V$(upstream_version).tar.gz
source_archive = ../$(OPK_SOURCE)-$(OPK_SOURCE_VERSION_UPSTREAM).orig.tar.gz

$(source_archive):
	wget -O '$@' "$(upstream_url)"

source: $(source_archive)