upstream_sf_base = http://downloads.sourceforge.net/project/tcl
upstream_path = Tcl/$(OPK_SOURCE_VERSION_UPSTREAM)
upstream_archive = tcl-core$(OPK_SOURCE_VERSION_UPSTREAM)-src.tar.gz
upstream_url = $(upstream_sf_base)/$(upstream_path)/$(upstream_archive)
source_archive = ../$(OPK_SOURCE)-$(OPK_SOURCE_VERSION_UPSTREAM).orig.tar.gz

$(source_archive):
	wget '$(upstream_url)'
	mv '$(upstream_archive)' '$(source_archive)'

source: $(source_archive)