dl_pack/bz2=bzip2 -c > $(1)
dl_pack/gz=gzip -nc > $(1)
dl_pack/xz=xz -zc -7e > $(1)
+dl_pack/zst=zstd -T0 --ultra -20 -c > $(1)
dl_pack/unknown=$(error ERROR: Unknown pack format for file $(1))
define dl_pack
$(if $(dl_pack/$(call ext,$(1))),$(dl_pack/$(call ext,$(1))),$(dl_pack/unknown))