This bug was fixed in the package dpkg - 1.17.5ubuntu5.8
--------------- dpkg (1.17.5ubuntu5.8) trusty; urgency=medium
* Add support for .deb archives with a control member not compressed (control.tar) or compressed with xz (control.tar.xz) LP: #1730627.
-- Adam Conrad <email address hidden> Mon, 04 Dec 2017 12:15:45 -0700
This bug was fixed in the package dpkg - 1.17.5ubuntu5.8
---------------
dpkg (1.17.5ubuntu5.8) trusty; urgency=medium
* Add support for .deb archives with a control member not compressed
(control.tar) or compressed with xz (control.tar.xz) LP: #1730627.
-- Adam Conrad <email address hidden> Mon, 04 Dec 2017 12:15:45 -0700