❯sudo apt list --upgradable
 Listing... Done
 debhelper/xenial,xenial 10.2.2ubuntu1~ubuntu16.04.1 all [upgradable from:9.20160115ubuntu3]
 N: There is 1 additional version. Please use the '-a' switch to see it

❯sudo dh -a
 dh: No compatibility level specified in debian/compat
 dh: This package will soon FTBFS; time to fix it!
 dh: Compatibility levels before 4 are no longer supported (level 1 requested)

sudo apt upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.