debian/changelog

+mesa (18.0.2-3) UNRELEASED; urgency=medium
+
+  [ Nicolas Braud-Santoni ]
+  * Add debian/gbp.conf.
+
+ -- Andreas Boll <aboll@debian.org>  Wed, 02 May 2018 19:42:26 +0200
+
 mesa (18.0.2-2) unstable; urgency=medium
 
   * Upload to unstable.

debian/gbp.conf

+[DEFAULT]
+debian-branch=debian-unstable
+upstream-branch=upstream-unstable