Currently upstream does not provide any release tarballs or release tags in git. Thus the .orig.tar.gz provided in the Debian archive is manually cut from the upstream git clone. E.g. git archive --format=tar.gz -o ~/debian/vym-2.9.27.tar.gz --prefix=vym-2.9.27/ d9d7b12a05dcffe3bf246cbb73e1cf718bd9dcd7 and imported with `gbp import-orig ../vym-2.9.27.tar.gz`.