Olly, thanks for fixing this bug. Since Ubuntu 16.10 has gcc 6 too, the patch should also be added to 00list.Ubuntu like this:
=== modified file 'debian/patches/00list.Ubuntu' --- debian/patches/00list.Ubuntu 2016-10-02 04:10:59 +0000 +++ debian/patches/00list.Ubuntu 2016-10-02 04:14:11 +0000 @@ -1,3 +1,3 @@ 01_ubuntu_changelog #10_ubuntu_maintenance_gui - +99_fix_build_with_gcc6 Thanks, Jeremy Bicha