diff -Nru ubuntu-dev-tools-0.163/debian/changelog ubuntu-dev-tools-0.164/debian/changelog
--- ubuntu-dev-tools-0.163/debian/changelog	2018-04-24 11:11:18.000000000 +0000
+++ ubuntu-dev-tools-0.164/debian/changelog	2018-04-24 11:24:43.000000000 +0000
@@ -1,3 +1,9 @@
+ubuntu-dev-tools (0.164) unstable; urgency=medium
+
+  * mk-sbuild: Initialise ubuntu_dist_ge vars so unknown releases work.
+
+ -- Adam Conrad <adconrad@ubuntu.com>  Tue, 24 Apr 2018 05:24:43 -0600
+
 ubuntu-dev-tools (0.163) unstable; urgency=medium
 
   * mk-sbuild: Add ubuntu_dist_ge and use it to set BUILD_PKGS for Ubuntu.
diff -Nru ubuntu-dev-tools-0.163/mk-sbuild ubuntu-dev-tools-0.164/mk-sbuild
--- ubuntu-dev-tools-0.163/mk-sbuild	2018-04-24 11:07:29.000000000 +0000
+++ ubuntu-dev-tools-0.164/mk-sbuild	2018-04-24 11:24:38.000000000 +0000
@@ -333,6 +333,8 @@
 if [ "$DISTRO" = "ubuntu" ]; then
     ubuntu_dist_ge() {
       local releases="$(ubuntu-distro-info --all)"
+      local left=999
+      local right=0
       local seq=1
       for i in $releases; do
         if [ $1 = $i ]; then